Some human traits controlled by a single gene

TABLE 4.1 Some Human Traits Controlled by Single Genes
AUTOSOMAL RECESSIVE TRAITS
Trait Phenotype MIM Number
Albinism Absence of pigment in skin, eyes, hair 203100
Ataxia telangiectaSia 3rogressive degeneration of nervous system 208900
Bloom syndrome Dwarfism; skin rash; increased cancer rate 210900
Cystic fibrosis Mucus production that blocks ducts of certain glands, 219700
ung passages; often fatal by early adulthood
Fanconi anemia Slow growth; heart defects; high rate of leukemia 227650
Galactosemia Accumulation of galactose in liver; mental retardation 230400
Phenylketonuria Excess accumulation of phenylalanine in blood; mental 261600
retardation
Sickle cell anemia Abnormal hemoglobin, blood vessel blockage; early 141900
death
Thalassemia mproper hemoglobin production; symptoms range 141900/
rom mild to fatal 141800
Xeroderma Lack of DNA repair enzymes, sensitivity to UV light; skin 278700
pigmentosum cancer; early death
Tay-Sacns disease mproper metabolism of gangliosides in nerve cells; 272800
early death
AUTOSOMAL DOMINANT TRAITS
Trait Phenotype MIM Number
Achondroplasia )warfism assooated With defects in growth regions of 100800
orig bones
Brachydactyly Malformed hands with shortened fingers 112500
Camptodactyly Stiff, permanently bent little fingers 114200
Crouzon syndrome Defective development of midfacral region, protruding 123500
eyes, hook nose
Ehlers-Danlos Connective tissue disorder, elastic skin, loose joints 130000
syndrome
Familial Elevated levels of cholesterol; predisposes to plaque 144010
hypercnolesterolemia formation, cardiac disease; may be most prevalent
genetic disease
Adult polycystic Formation of cysts in kidneys; leads to hypertension, 173900
kidney disease kidney failure
Huntington disease Progressive degeneration of nervous system; dementia; 143100
early death
Marfan syndrome Connective tissue defect; death by aortic rupture 154700
Nail-patella syndrome Absence of nails, kneecaps