II. Definitions

  1. Gene
    1. Core functional and physical unit of heredity, most forming a blueprint for Protein construction
    2. Each gene is encoded by a DNA segment, located in a specific position on a specific Chromosome
  2. Chromosome
    1. One of 23 pairs (46 total) of long DNA strands that are densely packaged into chromatin
    2. Each Chromosome houses 200-2000 genes (except the Y Chromosome which has only 50 genes)
  3. Allele
    1. Two Alleles (one from each parent) are inherited for each gene
  4. Homozygous
    1. For a given gene, the two inherited Alleles are the same
  5. Heterozygous
    1. For a given gene, the two inherited Alleles are different
  6. Genotype
    1. Genetic makeup of an individual (their collection of Alleles)
  7. Phenotype
    1. Genetic (Allele) expression resulting in observable characteristics or traits of an individual
  8. Genetic Polymorphism
    1. Natural variation in DNA, genes or Chromosomes
    2. Single Nucleotide polymorphism refers to gene variation in a single DNA base pair
  9. Autosomal Recessive Inheritance
    1. Conditions that manifest only if both Alleles of a gene mutation are inherited
  10. Autosomal Dominant Inheritance
    1. Conditions that manifests even if only one Allele of a gene mutation is inherited

IV. Causes: Delayed presentation (examples)

V. Exam: Congenital malformations (examples)

  1. Inner Epicanthal Folds
  2. Altered interpupillary distance
  3. Asymmetric limb size
  4. Hypopigmentation (hair, skin)
  5. Coloboma
  6. Tooth anomalies (e.g. single Maxillary central incisor)
  7. Cafe Au Lait spots
  8. Digit anomalies
    1. Syndactyly (fused digits)
    2. Tapered digits
    3. Clinodactyly (curved digits)
    4. Arachnodactyly (long, slender fingers)

VI. Precautions

  1. Home Genetic Tests (e.g. 23andMe)
    1. Patients mail in a cheek swab sample for DNA analysis
    2. Tests only a subset of available Genetic Tests at a cost of several hundred dollars
    3. Risk of both False Positives and false reassurance when testing is incomplete
    4. Genetic Counseling is preferred for test interpretation and test selection based on patient history
    5. (2018) Presc Lett 25(7): 41

VII. Resources

  1. AAP Diagnosis of common Genetic Syndromes
    1. http://www2.aap.org/visit/cmte18.htm
  2. Genetics - NIH
    1. http://ghr.nlm.nih.gov/
  3. American College of Medical Genetics
    1. http://www.acmg.net

Images: Related links to external sites (from Bing)

Related Studies

Ontology: Congenital Abnormality (C0000768)

Definition (NCI) Any abnormality, anatomical or biochemical, evident at birth or during the neonatal period.
Definition (MSH) Malformations of organs or body parts during development in utero.
Concepts Congenital Abnormality (T019)
MSH D000013
ICD9 759.9, 740-759.99
ICD10 Q89.9
SnomedCT 157028001, 205999005, 205842001, 157033002, 157034008, 268359006, 276654001, 112635002, 66091009, 443341004, 21390004, 107656002, 276655000, 385297003
English Deformity, Abnormalities, Congenital, Abnormality, Congenital, Birth Defects, Congenital Abnormality, Congenital Defects, Defect, Birth, Defect, Congenital, Defects, Birth, Defects, Congenital, Deformities, CONGENITAL ANOMALY NOS, Anomaly congenital, malformations, deformity, Congenital anomaly NOS, Congenital anomalies, Congenital malformation, unspecified, Fetal development abnormality, Birth Defect, Congenital Defect, Congenital Anomaly, CONGEN ABNORM, CONGEN DEFECTS, ABNORM CONGEN, DEFECTS CONGEN, Congenital Abnormalities, malformation, congenital malformations, congenital malformations (diagnosis), fetal anomaly (diagnosis), fetal anomaly, Congenital Anomaly or Birth Defect, Congenital abnormality NOS, Anomaly anomaly congen, Birth defects, Developmental disturbance, Congenital defect, Congenital deformity NOS, Congenital Abnormalities [Disease/Finding], congenital abnormality, dysmorphism, congenital anomaly, congenital defect, abnormal development, congenital deformity, developmental defect, dysmorphisms, congenital abnormalities, dysgenesis, birth defect, birth defects, fetal malformation, congenital defects, congenital malformation, Abnormalities, Congenital anomaly NOS (disorder), Birth defect, Congenital Anomalies of Fetus, DEFECT/DEFORMITY, CONGENITAL, CONGENITAL DEFECT/DEFORMITY, DEFORMITY/DEFECT, CONGENITAL, SCONG, Congenital malformation (morphologic abnormality), Congenital abnormality, Congenital anomaly (disorder), Foetal developmental abnormality, Fetal developmental abnormality, Foetal malformation, Developmental malformation, Developmental anomaly, Developmental defect, Congenital anomaly, Congenital malformation, Congenital deformity, Dysgenesis, Fetal malformation, CM - Congenital malformation, Abnormal development, Congenital anomaly (morphologic abnormality), Congenital deformity (disorder), Congenital deformity (morphologic abnormality), Congenital malformation (disorder), Developmental abnormality, Developmental anomaly (morphologic abnormality), Malformation, Anomalous formation, congenital; deformity, deformity; congenital, anomaly, Abnormal development, NOS, Anomalous formation, NOS, Congenital abnormality, NOS, Congenital anomaly, NOS, Congenital defect, NOS, Congenital deformity, NOS, Congenital malformation, NOS, Developmental anomaly, NOS, Developmental defect, NOS, Developmental malformation, NOS, Dysgenesis, NOS, Malformation, NOS, Congenital Anatomic Abnormality, Congenital Anatomical Abnormality, Congenital Deformity, Congenital Malformation, CONGENITAL ANOMALIES, Congenital anomaly, unspecified, congenital anomalies
Italian Anomalia congenita, Malformazione fetale, Anomalie congenite, non specificate, Malformazione congenita, Difetti alla nascita, Malformazione congenita NAS, Anomalia congenita NAS, Alterazione dello sviluppo, Deformità, Anomalie congenite, Difetti, Difetti congeniti
Dutch congenitale anomalie anomalie, geboortedefecten, congenitale anomalie NAO, congenitale anomalie, niet-gespecificeerd, afwijking NAO, congenitaal, ontwikkelingsstoornis, congenitaal; misvorming, misvorming; congenitaal, Congenitale misvorming, niet gespecificeerd, congenitale anomalie, foetale misvorming
French Anomalie congén, Anomalie congénitale SAI, Trouble développemental, Anomalie congénitale non précisée, Anomalie morphologique congénitale, Anomalies morphologiques congénitales, Malformation, Anomalies congénitales, Anomalie congénitale, ANOMALIE CONGENITALE SAI, Malformation foetale, Malformations, Malformations congénitales, Difformités congénitales
German kongenitale Anomalie, unspezifisch, Geburtsfehler, Anomalie, kongenital, kongenitale Anomalie NNB, Entwicklungsstoerung, ANGEBORENE MISSBILDUNG NNB, Angeborene Fehlbildung, nicht naeher bezeichnet, fetale Missbildung, kongenitale Anomalie, Fehlbildungen, angeborene, Kongenitale Fehlbildungen, Angeborene Fehlbildungen, Abnormalitäten, Abnormitäten, Deformitäten, Geburtsschäden
Portuguese Perturbação de desevolvimento, Anomalia congénita NE, Defeitos congénitos, Anormalidades Congênitas, ANOMALIA CONGENITA NE, Anormalidade Congênita, Anomalia Congênita, Anomalias Congênitas, Malformações, Anomalia congénita, Malformação fetal, Defeitos Congênitos, Deformidades
Spanish Anormalidad congénita NEOM, Anomalía congénita no especificada, Anomalía congénita NEOM, Defectos de nacimiento, Alteración del desarrollo, Anomalías Congénitas, ANOMALIA CONGENITA SE, anomalía congénita (trastorno), anomalía congénita, SAI, anomalía congénita, SAI (trastorno), Congenital anomaly NOS, Anomalía Congénita, Malformaciones, anomalía congénita (anomalía morfológica), anomalía congénita, anormalidad congénita, defecto congénito, deformidad congénita (anomalía morfológica), deformidad congénita (trastorno), deformidad congénita, deformidad del desarrollo (anomalía morfológica), deformidad del desarrollo, desarrollo anormal, disgenesia, malformación congénita (anomalía morfológica), malformación congénita (trastorno), malformación congénita, malformación fetal, Anomalía congénita, Malformación fetal, Defectos Congénitos, Deformidades
Japanese 発育障害, 胎児奇形, 先天性欠損, 先天異常NOS, 先天異常, センテンイジョウNOS, センテンセイケッソン, タイジキケイ, ハツイクショウガイ, センテンイジョウ, 奇形, 先天奇形, 先天性欠損(奇形), 形成異常, 先天性異常(奇形)
Czech kongenitální defekty, deformity, Vrozená anomálie, blíže neurčená, Odlišná anomálie vrozená, Vrozená vada, Fetální malformace, Vrozená anomálie, Vrozená abnormalita NOS, Vrozená anomálie NOS, Vývojová porucha, Porodní defekty, vrozené abnormality, vrozené vady
Finnish Synnynnäiset epämuodostumat
Swedish Medfödda missbildningar
Korean 상세불명의 선천 기형
Latvian Not Translated[Congenital Abnormalities]
Polish Defekty wrodzone, Wady wrodzone, Nieprawidłowości wrodzone, Rozwojowe wady wrodzone
Hungarian Magzati malformatio, Veleszületett anomalia k.m.n., Congenitalis anomalia, nem meghatározott, Fejlődési zavar, Veleszületett rendellenesség k.m.n., Születési hibák, Congenitalis anomalia, Congenitális rendellenesség, Veleszületett anomalia
Norwegian Medfødte misdannelser, Kongenitale misdannelser, Fødselsdefekter, Deformiteter

Ontology: Alleles (C0002085)

Definition (NCI_NCI-GLOSS) One of two or more DNA sequences occurring at a particular gene locus. Typically one allele (normal DNA sequence) is common, and other alleles (mutations) are rare.
Definition (NCI) Mutually exclusive alternative forms of the same gene occupying the same locus on homologous chromosomes, differing in nucleotide sequence and governing the same biochemical and developmental process.
Definition (CSP) one of a series of possible alternative forms of a given gene, differing in DNA sequence, and affecting the functioning of a single product.
Definition (MSH) Variant forms of the same gene, occupying the same locus on homologous CHROMOSOMES, and governing the variants in production of the same gene product.
Concepts Gene or Genome (T028)
MSH D000483
SnomedCT 9109004
English Alleles, Allelomorph, Allelomorphs, allelic gene, allele, alleles, Genetic alleles, Genetic alleles (finding), Allele
Swedish Alleler
Czech alely
Finnish Alleelit
Italian Allelomorfi, Alleli
French Gènes allélomorphes, Allèles
Polish Allele
Japanese 対立遺伝子, アリル(遺伝子), 対立因子(遺伝学), 対立因子, 対立形質(遺伝学), 対立形質, 遺伝単位, 遺伝子-対立, アレル(遺伝子)
Spanish alelomorfos, alelos genéticos (hallazgo), alelos genéticos, Alelomorfos, Alelos
German Allele, Allelomorphe
Dutch Allel, Allelomorfen
Portuguese Alelomorfos, Alelos

Ontology: Chromosomes (C0008633)

Definition (FMA) Organelle part which consists of nucleotides arranged linearly into three regions, DNA replication origin, centromere and telomere. Examples: nuclear chromosome, sex chromosome.
Definition (NCI) One of the bodies in the cell nucleus that is the bearer of genes, has the form of a delicate chromatin filament during interphase, contracts to form a compact cylinder segmented into two arms by the centromere during metaphase and anaphase stages of cell division, and is capable of reproducing its physical and chemical structure through successive cell divisions.
Definition (NCI_NCI-GLOSS) Part of a cell that contains genetic information. Except for sperm and eggs, all human cells contain 46 chromosomes.
Definition (MSH) In a prokaryotic cell or in the nucleus of a eukaryotic cell, a structure consisting of or containing DNA which carries the genetic information essential to the cell. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)
Definition (CSP) in a prokaryotic cell or in the nucleus of a eukaryotic cell, a structure containing DNA which carries the genetic information essential to the cell; the bacterial chromosome is a closed circle of double stranded DNA associated with the cell membrane; nuclear chromosomes are associated with RNA, histones and non histone proteins; the normal number of chromosomes in human somatic cells is 46.
Definition (GO) A structure composed of a very long molecule of DNA and associated proteins (e.g. histones) that carries hereditary information. [ISBN:0198547684]
Concepts Cell Component (T026)
MSH D002875
SnomedCT 91272006
LNC LP20948-3, LP32750-9, MTHU047638
Swedish Kromosomer
English Chromosomal, chromosomes, chromosome, Chromosome, Chromosome (cell structure), Chromosome, NOS, Chromosome (body structure), Chromosomes
Czech chromozómy
Finnish Kromosomit
Latvian Hromosomas
Polish Chromosomy
Norwegian Kromosomer
Portuguese Cromossomas, Cromossomos
Spanish cromosoma (estructura celular), cromosoma (estructura corporal), cromosoma, Cromosomas
French Chromosomes
German Chromosomen
Italian Cromosomi
Dutch Chromosomen, Chromosoom

Ontology: Genes (C0017337)

Definition (MSH) A category of nucleic acid sequences that function as units of heredity and which code for the basic instructions for the development, reproduction, and maintenance of organisms.
Definition (HL7V3.0) <p><b>Description:</b>A DNA segment that contributes to phenotype/function. In the absence of demonstrated function a gene may be characterized by sequence, transcription or homology</p>
Definition (NCI) A functional unit of heredity which occupies a specific position on a particular chromosome and serves as the template for a product that contributes to a phenotype or a biological function.
Definition (NCI_NCI-GLOSS) The functional and physical unit of heredity passed from parent to offspring. Genes are pieces of DNA, and most genes contain the information for making a specific protein.
Definition (CSP) segment of the genome that codes for a functional product.
Concepts Gene or Genome (T028)
MSH D005796
SnomedCT 67271001
LNC LP32747-5
English Genes, genes, Gene (substance), gene, Gene, NOS, Gene
Swedish Gener
Czech geny, gen
Finnish Geenit
Italian Gene, Geni
Japanese 分断された遺伝子, 遺伝子, 遺伝子-分断, 分断遺伝子, 構造遺伝子, 遺伝子-構造, 遺伝子-分化, 分化遺伝子, シストロン
Croatian GENI
Polish Geny
Norwegian Not Translated[Genes]
Spanish gen (sustancia), gen, Genes
French Gènes, Gène
German Gene
Dutch Gen, Genen
Portuguese Genes

Ontology: Genetic Counseling (C0017382)

Definition (MEDLINEPLUS)

Genetic counseling provides information and support to people who have, or may be at risk for, genetic disorders. A genetic counselor meets with you to discuss genetic risks. The counseling may be for yourself or a family member. Or you may get it when you are planning or expecting a baby. You may follow up with genetic testing.

There are many reasons to seek genetic counseling. You may consider it if you

  • Have a personal or family history of a genetic condition or birth defect
  • Are pregnant or planning to be pregnant after age 35
  • Already have a child with a genetic disorder or birth defect
  • Have had two or more pregnancy losses or a baby who died
  • Have had ultrasound or screening tests that suggest a possible problem

Genetics Home Reference

Definition (NCI_NCI-GLOSS) A communication process between a specially trained health professional and a person concerned about the genetic risk of disease. The person's family and personal medical history may be discussed, and counseling may lead to genetic testing.
Definition (NCI) The process whereby an expert in hereditary disorders provides information about risk and clinical burden of a disorder or disorders to patients or relatives in families with genetic disorders as an aid to making informed and responsible decisions about marriage, children, early diagnosis, and handling disability.
Definition (MSH) An educational process that provides information and advice to individuals or families about a genetic condition that may affect them. The purpose is to help individuals make informed decisions about marriage, reproduction, and other health management issues based on information about the genetic disease, the available diagnostic tests, and management programs. Psychosocial support is usually offered.
Definition (PSY) Presentation and discussion, usually with prospective parents, of factors involved in potential inheritance of disorders.
Definition (CSP) educational process that provides information and advice to individuals or families about a genetic condition that may affect them; the purpose is to help individuals make informed decisions about marriage, reproduction, and other health management issues based on information about the genetic disease, the available diagnostic tests, and management programs; psychosocial support is usually offered.
Definition (NIC) Use of an interactive helping process focusing on assisting an individual, family, or group, manifesting or at risk for developing or transmitting a birth defect or genetic condition, to cope
Definition (ALT) Providing a client/patient with education and/or information regarding genetics to prevent and/or minimize risk of his or her passing a genetic disorder(s). Service is billed in 15-minute increments.
Concepts Therapeutic or Preventive Procedure (T061)
MSH D005817
SnomedCT 148239004, 79841006
English Counseling, Genetic, Genetic Counseling, GENET COUNSELING, COUNSELING GENET, genetic counselling, Genetic Counselling, Genetic counselling (regime/therapy), genetic counseling (treatment), Genetic counseling, Genetic counselling, genetic counseling, Genetic counseling individual each 15 minutes, gntk cnslng ndvdl ea.15min, Counseling;genetic, Counselling;genetic, Genetic counseling (procedure), Genetic counseling (regime/therapy)
Spanish asesoramiento genético (procedimiento), asesoramiento genético (régimen/tratamiento), Asesoramiento Genético, Asesoría Genética, Consejo Genético, asesoramiento genético, Consejo genético
Italian Consigli e test di genetica, Counseling genetico
Swedish Genetisk rådgivning
Japanese イデンソウダン, 遺伝カウンセリング, 遺伝相談, カウンセリング-遺伝
Czech genetické poradenství, Genetické poradenství
Finnish Perinnöllisyysneuvonta
Polish Poradnictwo genetyczne, Prenatalne poradnictwo genetyczne
Hungarian Genetikai tanácsadás
Norwegian Genetisk veiledning, Genetisk rådgivning
Portuguese Aconselhamento genético, Aconselhamento Genético
Dutch genetic counselling / erfelijkheidsvoorlichting, Erfelijkheidsvoorlichting, Genetic counselling, Voorlichting, erfelijkheids-
German Genberatung, Genetische Beratung
French Conseil génétique

Ontology: genetic aspects (C0017399)

Definition (MSH) Used for mechanisms of heredity and the genetics of organisms, for the genetic basis of normal and pathologic states, and for the genetic aspects of endogenous chemicals. It includes biochemical and molecular influence on genetic material.
Concepts Biologic Function (T038)
MSH Q000235
ICD9 V83-V84.99
English GENETICS, GENET, GE, genetic aspects, genetics

Ontology: Genotype (C0017431)

Definition (MSH) The genetic constitution of the individual, comprising the ALLELES present at each GENETIC LOCUS.
Definition (NCI_NCI-GLOSS) At its broadest level, genotype includes the entire genetic constitution of an individual. It is often applied more narrowly to the set of alleles present at one or more specific loci.
Definition (NCI) The genetic constitution of an organism or cell, as distinct from its expressed features or phenotype.
Definition (CSP) entire genetic constitution of an individual; the alleles present at one or more specific loci.
Concepts Organism Attribute (T032)
MSH D005838
SnomedCT 168488007, 34345003, 145681002
LNC LP29254-7
Swedish Genotyp
English Genotypic, genotypes, genotype, Genotype (procedure), Genotype (substance), Genotype (finding), Genotype, Genotypes
Czech genotyp
Finnish Genotyyppi
Croatian GENOTIP
Polish Genotyp
Norwegian Not Translated[Genotype]
Spanish genotipo, genotipo (sustancia), Genotipos, Genotipo
Portuguese Genótipos, Genótipo
French Génotype
German Genotyp
Italian Genotipo
Dutch Genotype

Ontology: Hereditary Diseases (C0019247)

Definition (MEDLINEPLUS)

Genes are the building blocks of heredity. They are passed from parent to child. They hold DNA, the instructions for making proteins. Proteins do most of the work in cells. They move molecules from one place to another, build structures, break down toxins, and do many other maintenance jobs.

Sometimes there is a mutation, a change in a gene or genes. The mutation changes the gene's instructions for making a protein, so the protein does not work properly or is missing entirely. This can cause a medical condition called a genetic disorder.

You can inherit a gene mutation from one or both parents. A mutation can also happen during your lifetime.

There are three types of genetic disorders:

  • Single-gene disorders, where a mutation affects one gene. Sickle cell anemia is an example.
  • Chromosomal disorders, where chromosomes (or parts of chromosomes) are missing or changed. Chromosomes are the structures that hold our genes. Down syndrome is a chromosomal disorder.
  • Complex disorders, where there are mutations in two or more genes. Often your lifestyle and environment also play a role. Colon cancer is an example.

Genetic tests on blood and other tissue can identify genetic disorders.

NIH: National Library of Medicine

Definition (NCI) Genetic diseases are diseases in which inherited genes predispose to increased risk. The genetic disorders associated with cancer often result from an alteration or mutation in a single gene. The diseases range from rare dominant cancer family syndrome to familial tendencies in which low-penetrance genes may interact with other genes or environmental factors to induce cancer. Research may involve clinical, epidemiologic, and laboratory studies of persons, families, and populations at high risk of these disorders.
Definition (MSH) Diseases caused by genetic mutations that are inherited from a parent's genome.
Definition (CSP) general term for any disorder caused by a genetic mechanism, comprising chromosome aberrations or anomalies, mendelian or monogenic or single-gene disorders, and multifactorial disorders; note that all genetic disorders are not treed under this term; see RTs for others; in addition, many disorders not treed here or under RTs may have a genetic component.
Concepts Disease or Syndrome (T047)
MSH D030342
SnomedCT 264530000, 32895009
English Disease, Hereditary, Diseases, Hereditary, Hereditary Disease, genetic disorder, HEREDITARY DIS, hereditary disorder, heritable disorder, Hereditary Diseases, Hereditary disorder NOS, genetics disease, hereditary disorders, hereditary disease, inherited disease, genetic disorders, diseases hereditary, genetic disease, hereditary diseases, Inherited Disease, Genetic Disorders, Hereditary disorder, Hereditary disease, Genetic disease, Hereditary disease (disorder), Inherited disease, genetic condition, Genetic disease, NOS, Hereditary disease, NOS, Inherited disease, NOS, Hereditary Disorders, Genetic Disorder, Genetic Condition, Molecular Disease
Italian Disturbo ereditario, Disturbo ereditario NAS, Malattie ededitarie
Dutch erfelijke aandoening NAO, erfelijke aandoening, Erfelijke ziekten
French Anomalie héréditaire SAI, Maladies héréditaires, Anomalie héréditaire, Maladie héréditaire
German Erbkrankheit NNB, Erbkrankheiten, Erbkrankheit, Hereditäre Krankheiten
Portuguese Afecção hereditária NE, Doenças Hereditárias, Afecção hereditária
Spanish Trastorno hereditario NEOM, Enfermedades Hereditarias, enfermedad genética, enfermedad heredada, enfermedad hereditaria (trastorno), enfermedad hereditaria, Trastorno hereditario
Japanese 遺伝性障害, 遺伝性障害NOS, イデンセイショウガイNOS, イデンセイショウガイ
Czech dědičné nemoci, Dědičná porucha, Hereditární onemocnění NOS
Hungarian Öröklött betegség k.m.n., Öröklött betegség
Norwegian Hereditære sykdommer, Arvelige sykdommer

Ontology: Heterozygote (C0019425)

Definition (NCI) Having two different allelic forms of a gene, one inherited from each parent, on each of the two homologous chromosomes.
Definition (NCI_NCI-GLOSS) Occurs when the two alleles at a particular gene locus are different. A heterozygous genotype may include one normal allele and one mutation, or two different mutations. The latter is called a compound heterozygote.
Definition (MSH) An individual having different alleles at one or more loci regarding a specific character.
Definition (CSP) having different alleles at one or more loci in homologous chromosome segments.
Concepts Organism Attribute (T032)
MSH D006579
SnomedCT 14556007
English Heterozygote, Heterozygotes, Heterozygous, Heterozygosity, heterozygote, heterozygotes, heterozygous genotype, Heterozygote (qualifier value)
Swedish Heterozygot
Czech heterozygot
Finnish Heterotsygootti
Japanese 接合体-異型, 遺伝キャリア, 接合体-ヘテロ, 接合体-異種, 異種接合体, キャリア-遺伝子, ヘテロ接合体, 異型接合体
Polish Heterozygota
Croatian Heterozigot
Spanish heterocigoto (calificador), heterocigoto, Heterocigoto
French Hétérozygote
German Heterozygot
Italian Eterozigoti
Dutch Heterozygoot
Portuguese Heterozigoto

Ontology: Homozygote (C0019904)

Definition (NCI) Having two identical allelic forms of a gene, one inherited from each parent, on each of the two homologous chromosomes.
Definition (NCI_NCI-GLOSS) Occurs when both alleles at a particular gene locus are the same. A person may be homozygous for the normal allele or for a mutation.
Definition (MSH) An individual in which both alleles at a given locus are identical.
Definition (CSP) an individual or cell characterized by having identical alleles at one or more loci in homologous chromosome segments.
Concepts Organism Attribute (T032)
MSH D006720
SnomedCT 22061001
English Homozygote, Homozygotes, Homozygosity, Homozygous, homozygote, homozygous genotype, Homozygote (finding)
Swedish Homozygot
Czech homozygot
Finnish Homotsygootti
Polish Homozygota
Spanish homocigoto (hallazgo), homocigoto, Homocigoto
French Homozygote
German Homozygot
Italian Omozigote
Dutch Homozygoot
Portuguese Homozigoto

Ontology: Phenotype (C0031437)

Definition (HL7V3.0) <p><b>Description:</b>A genomic phenomenon that is expressed externally in the organism.</p>
Definition (NCI) The assemblage of traits or outward appearance of an individual. It is the product of interactions between genes and between genes and the environment.
Definition (NCI_NCI-GLOSS) The observable characteristics in an individual resulting from the expression of genes; the clinical presentation of an individual with a particular genotype.
Definition (MSH) The outward appearance of the individual. It is the product of interactions between genes, and between the GENOTYPE and the environment.
Definition (CSP) the entire physical, biochemical, and physiological makeup of an individual as determined both genetically and environmentally; also, any one or any group of such traits.
Concepts Organism Attribute (T032)
MSH D010641
SnomedCT 8116006, 365831004, 145678007, 168485005
Swedish Fenotyp
Czech fenotyp
Finnish Fenotyyppi
English Phenotype finding, phenotype, phenotypes, Finding of phenotype (finding), Phenotype - finding, Phenotype (finding), Phenotypic expression, Phenotype finding (finding), Phenotype, Phenotypes
Croatian FENOTIP
Polish Fenotyp
Norwegian Not Translated[Phenotype]
Spanish fenotipo, expresión fenotípica, fenotipo (hallazgo), Fenotipo
French Phénotype
German Phänotyp
Italian Fenotipo
Dutch Fenotype
Portuguese Fenótipo

Ontology: Autosomal recessive inheritance (C0441748)

Definition (NCI_NCI-GLOSS) Autosomal recessive inheritance refers to genetic conditions that occur only when mutations are present in both copies of a given gene (i.e., the person is homozygous for a mutation, or carries two different mutations of the same gene, a state referred to as compound heterozygosity).
Concepts Intellectual Product (T170)
SnomedCT 258211005
English Autosom recessive inheritance, autosomal inheritance recessive, autosomal recessive, autosomal recessive inheritance, recessive autosomal inheritance, autosomal recessives, Autosomal Recessive Inheritance, Autosomal recessive, Autosomal recessive inheritance, Autosomal recessive inheritance (qualifier value)
Spanish herencia autosómica recesiva (calificador), herencia autosómica recesiva

Ontology: Autosomal dominant inheritance (C0443147)

Definition (NCI_NCI-GLOSS) Autosomal dominant inheritance refers to genetic conditions that occur when a mutation is present in one copy of a given gene (i.e., the person is heterozygous).
Concepts Intellectual Product (T170)
SnomedCT 263681008
English Autosomal dominant inheritance, autosomal dominant, autosomal dominant inheritance, Autosomal Dominant Inheritance, Autosomal dominant, AD - Autosomal dominant, Autosomal dominant inheritance (qualifier value)
Spanish autosómico dominante, herencia autosómica dominante (calificador), herencia autosómica dominante

Ontology: Genetic syndrome (C0567439)

Concepts Disease or Syndrome (T047)
SnomedCT 290028006
English genetic syndromes, genetic disorder syndrome, genetics syndrome, genetic syndrome, syndrome genetic, disorders genetic syndrome, syndrome genetic disorder, genetics syndromes, Genetic syndrome, Genetic syndrome (disorder)
Spanish síndrome genético (trastorno), síndrome genético

Ontology: gene polymorphism (C0678951)

Concepts Genetic Function (T045)
English gene polymorphism, gene polymorphisms

Ontology: Genetic screening method (C0679560)

Definition (MSH) Detection of a MUTATION; GENOTYPE; KARYOTYPE; or specific ALLELES associated with genetic traits, heritable diseases, or predisposition to a disease, or that may lead to the disease in descendants. It includes prenatal genetic testing.
Definition (MEDLINEPLUS)

Genetic tests are tests on blood and other tissue to find genetic disorders. Over 2000 tests are available. Doctors use genetic tests for several reasons. These include

  • Finding genetic diseases in unborn babies
  • Finding out if people carry a gene for a disease and might pass it on to their children
  • Screening embryos for disease
  • Testing for genetic diseases in adults before they cause symptoms
  • Making a diagnosis in a person who has disease symptoms
  • Figuring out the type or dose of a medicine that is best for a certain person

People have many different reasons for being tested or not being tested. For some, it is important to know whether a disease can be prevented or treated if a test is positive. In some cases, there is no treatment. But test results might help a person make life decisions, such as family planning or insurance coverage. A genetic counselor can provide information about the pros and cons of testing.

NIH: National Human Genome Research Institute

Definition (NCI_NCI-GLOSS) Analyzing DNA to look for a genetic alteration that may indicate an increased risk for developing a specific disease or disorder.
Definition (NCI) The process of isolating and testing the DNA of an embryo or a person to detect the presence of genetic alterations or defects that may predispose to the future development of a disease or disorder.
Definition (PSY) Screening for presence or predisposition to a particular trait or disease that may be passed on to one's offspring.
Concepts Laboratory Procedure (T059)
MSH D005820
SnomedCT 405824009
CPT 88274, 88275
English genetic testing [select method/result first, then analyte], genetic screening method, genetic testing, Testing, Genetic, Genetic Testing, Genetic screening method, Genetic Examination, genetic tests, genetics test, testing genetic, genetics testing, genetic screening test, Genetic testing, genetic testing (procedure), Genetic Test, genetic analysis, Genetic test (procedure), Genetic test, genetic test, Test;genetic
French Analyse génétique
German Genetischer Test, Gentest, Genetische Testung
Italian Testing genetico
Portuguese Testes Genéticos
Spanish Pruebas Genéticas, Tamizado Genético, Tamización Genética, Tamizaje Genético, Prospección Genética, prueba genética (procedimiento), prueba genética
Czech genetické vyšetření, genetické testování
Swedish Gentester
Polish Skrining genetyczny, Badania predyspozycji genetycznych, Testy genetyczne, Badania genetyczne
Japanese 遺伝学的スクリーニング
Norwegian Gentesting