Therefore, determination of the true gene frequencies and gene prevalences of PiS and PiZ, the most common abnormal AAT alleles, in addition to factors affecting phenotypic
penetrance are high priorities of those groups that support screening and detection programs.
A consensus conference convened in 1997 by the Centers for Disease Control and Prevention and the National Human Genome Research Institute did not recommend genetic testing, although it did urge that high priority be given to population-based research to clarify issues such as age- and sex-related
penetrance of genotypes and the psychosocial implications of screening (JAMA 280[2]:172-78, 1998).
Tuberous sclerosis complex is an autosomal-dominant disease with variable
penetrance affecting 1 in 10 000 people and is associated with 1 of 2 tumor suppressor genes, TSC1 (chromosome 9q34) and TSC2 (chromosome 16p13.3).[3,4] Approximately 40% of patients with tuberous sclerosis have a familial form, and these have an equal association with TSC1 and TSC2 defects.
However, because of genetic phenomena known as incomplete
penetrance and variable expressivity, most Waardenburg's patients do not exhibit all of the syndrome's characteristic traits.
INTRODUCTION: Porokeratosis is an autosomal dominant genodermatosis with variable
penetrance, characterized by a clonal disorder of keratinization with one or more atrophic patches surrounded by a clinically and histologically distinctive hyperkeratotic ridge like border called the cornoid lamella.
Bottom-up Market Survey Data: Qualitative and Quantitative Market AnalysisProduct Vendors and their
Penetrance into the Research Market
The 22g11.2 duplication syndrome shows variable
penetrance and expressivity, with shared features of DiGeorge/velocardiofacial syndrome.
"I know of no other condition that predicts Parkinson's disease with that high a degree of
penetrance," he said.
It is autosomal dominant and has near complete
penetrance by age 20 years.
Lipoid proteinosis (Urbach-Wiethe disease, hyalinosis cutis et mucosae) is an autosomal-recessive condition with variable
penetrance. It is characterised by distinctive skin and mucous membrane lesions, particularly on the eyelids, on the extensor surface of large joints and in the mouth.
(4) The disease may be inherited as an autosomal-dominant trait with variable
penetrance in 50% of patients, or it may occur as a result of a spontaneous mutation.