allele
any of the alternative forms of a given gene.
aneuploidy
a condition in which extra or fewer copies of particular genes or chromosomal regions are present compared with the wild type.
autosomal dominant
a pattern of inheritance in which an affected individual has one copy of a mutant gene and one normal gene on a pair of autosomal chromosomes. Individuals with autosomal dominant disease have a 50:50 chance of passing the mutant gene, and therefore the disorder to their children
autosomes
all chromosomes other than the sex chromosomes
chromosomal aberration
alteration in the number or physical structure of chromosomes
codon
a sequence of three adjacent nucleotides in an mRNA molecule, specifying either an amino acid or a stop signal in protein synthesis
consanguinity
degree of relationship between person who depend from a common ancestor
degenerate
a feature of the genetic code in which an amino acid corresponds to more than one codon.
germinal mutation
a mutation that takes place in a reproductive cell
hemizygous
someone who only has one member of a chromosome pair or chromosome segment rather than the usual two; refers in particular to x-linked genes in males who under usual circumstance have only one x chromosome
heterozygous
carrying dissimilar alleles of one or more genes: not homozygous
homozygous
having the same allele of a gene in homologous chromosomes
inversion
a structural abberation in a chromosome in which the order of several genes is reversed from the normal order.
Locus
the site or position of a particular gene on a chromosome
monogenic
of or relating to, or controlled by a single gene, especially by either of an allelic pair
monosomy
a condition in which one member of a pair of chromosomes is missing
nondisjunction
failure of chromosomes to serparate (disjoin) and move to opposite poles of the division spindle; resulting in the loss or gain of a chromosome
polysomy
condition of a diploid cell or organism that has three or more copies of a particular chromosome
diploid
relating to a cel or nucleus containing two sets of chromosomes, one from each parent
recessive
refers to an allele, or the corresponding phenotypic trait, that is expressed only in homozygotes
somatic cell
any cell in the human body other than the sperm or egg cells. diploid cells
translocation
a mutation results rom an exchange of parts of two chromosomes
truncated protein
a protein that does not achieve its full length or its proper from, and thus is missing some of the amino acid residues that are present in a normal protein.
CFTR gene
codes for a protein involved in chloride and water transport across membranes. In cystic fibrosis, resulting in production of thick and sticky mucus that obstructs the airways in the lungs and the ducts in the pancreas.
cystic fibrosis
a congenital metabolic disorder, autosomal recessive, excessively viscid mucus causes obstruction of passage ways
Karyotype
the chromosome complement of a cell or organism, often according to their lengths and postions of their centromeres
penetrance
the proportion of organisms having a particular genotype that actually express the corresponding phenotype. If the phenotype is always expressed there is complete penetrance
PKU
Phenylketonuria: a hereditary condition resulting from inability to convert phyenylalnine into tyrosine. it causes severe mental retardation unless treated in infancy by a low phenylalanine diet.