Immunohematology Genetics Flashcards

Vocabulary flashcards covering cellular genetics, Mendelian inheritance laws, blood group systems, gene interactions, and pedigree analysis for immunohematology review.

Genome

The full complement of genes in an organism.

Chromosome

Double-stranded DNA structure which carries genetic information.

Gene

A unit of inheritance encoding a protein.

Locus

The specific, fixed position of a gene on a chromosome.

Allele

One or several alternative forms of a gene at a specific locus.

Genotype

The inheritance of actual genes from each parent.

Phenotype

The physical expression of inherited traits, such as the presence or absence of an antigen on a red blood cell.

Haplotype

Alleles inherited together on the same chromosome.

Amorph

A 'silent gene' that does not produce any obvious detectable traits.

Antithetical Antigens

Antigens encoded by alleles at the same locus.

Polymorphic

Having 2 or more alleles at a given locus.

Codominance

A pattern of inheritance in which both traits are expressed phenotypically.

Homozygous

An individual who has two identical alleles for a gene.

Heterozygous

An individual who inherits a different allele for a gene from each parent.

Dosage Effect

Variations in agglutination reaction intensity caused by differences in antigen density between homozygous and heterozygous gene expression.

Independent Segregation

Mendel's law stating that either allele can be passed to the next generation without having a permanent effect on one another.

Independent Assortment

Mendel's law stating that the inheritance of genes on different chromosomes gives separate and discrete antigen expression, allowing for all possible gene combinations.

Cis Position

Gene inheritance occurring on the same chromosome.

Trans Position

Gene inheritance occurring on opposite chromosomes.

Cis vs Trans Positional Interaction

The positional relationship of inherited genes on the same chromosome (cis) or opposite chromosomes (trans), which can affect gene interactions and antigen expression.

Linkage Disequilibrium

A condition in which haplotypes occur in a population at a frequency different from what would be expected by chance.

Crossing Over

The exchange of genetic material during meiosis after pairs have been replicated, resulting in two new and different chromosomes.

Population Genetics

The statistical application of genetic principles to determine genotype and phenotype occurrence within a population.

Propositus

The interesting or important member of a pedigree (referred to as the index case) who is often the primary reason the analysis is undertaken.

Chromatin

Long polymers of DNA and histones compressed and coiled to form chromosomes.

Mitosis

Somatic cell division that allows genetic material to replicate and transmit identical chromosomes to daughter cells.

Meiosis

Cell division occurring in gametes.

Red Cell Antigens

Inherited traits composed of proteins or carbohydrates linked to lipids or proteins on the RBC membrane that can elicit the production of a corresponding antibody in individuals who lack them.

Blood Group System

A system composed of antigens produced by alleles at a single genetic locus, or loci so closely linked that crossing over rarely occurs.

Pedigree Symbols Reference

A standardized chart of symbols representing family relationships, sex, generations (Roman numerals), offspring birth order, and clinical/carrier statuses in genetic analysis.

Autosomal Recessive Pedigree Pattern

An inheritance diagram showing traits that skip generations and affect individuals homozygous for the recessive gene.

X-Linked Recessive Pedigree Pattern

An inheritance pattern where affected males never pass the trait to their sons but produce carrier daughters.

Antigen-Negative Frequency Calculation

A method to calculate compatible donor blood probability by multiplying individual antigen-negative percentages; for instance, finding K-negative ($90\%$) and S-negative ($50\%$) donors yields $0.90 \times 0.50 = 0.45$ or $45\%$.