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 280:172-78, 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.