An hereditary disorder caused by a mutant allele of a single gene. Example: Huntington disease. SNP (single-nucleotide polymorphism) A SNP is a single-base variation that occurs about every 1,000 bases along the three billion base pairs of the human genome. The most common SNP is a change from cytosine to thymine (C - T) on one strand of DNA, with a change from guanine to adenine (G - A) on the complementary strand.
A disorder caused by a mutation in a single gene e.g. Cystic Fibrosis is due to CFTR mutations
The presence of an allele in either single dose (dominant disorders in males or females, X-linked disorders in males), or double dose (recessive disorders), accounts for the presence of disease. The inheritance of these disorders follow the ratios first described by Gregor Mendel.
Disease whose inheritance is controlled by one pair of genes (one on each homologous chromosome).
Hereditary disorder caused by a mutant allele of a single gene (e.g., Duchenne muscular dystrophy, retinoblastoma, sickle cell disease).
An inherited condition caused by a mutant allele at a single locus in the DNA; such a trait is monogenic (eg, Duchenne muscular dystrophy and sickle cell disease).