Genetics Northern California

Glossary

TermDescription
Autosomal dominantRefers to one of several inheritance patterns for single gene disorders, equally likely in both males and females. Autosomal means that both males and females can manifest symptoms of the disorder. Dominant means that of the two copies of each gene we carry, only one needs to be mutated in order to develop symptoms of the condition. Most lipid problems are inherited in this manner.
FAP (familial adenomatous polyposis)

An autosomal dominantly inherited predisposition to multiple adenomatous polyps of the colon and a high risk of colon cancer.

HNPCC

Hereditary nonpolyposis colorectal cancer. Autosomal dominantly inherited disease predisposing to colorectal cancer. May be in association with carcinoma of the endometrium, ovary, stomach, small bowel, and pancreas.

Osteogenesis Imperfecta (OI)

This condition is more commonly known as "brittle bone disease" as individuals with OI have bones that break very easily. This is caused by a disorder of type I collagen in which the collagen is either improperly formed or less than a normal amount is produced. There are 4 major classifications of OI:

Type 1: mild, most common, most fractures before puberty

Type 2: lethal neonatally

Type 3: severe, short statured, 100+ fractures, bone deformities, hearing loss, dental abnormalities

Type 4: mild-moderate, shorter than average

It is believed that most cases of OI are autosomal dominant.