Focused Boards Genetic Conditions

The conditions outlined on the ABGC study guide list

What two genes are associated w/ Alagille syndrome? Inheritance pattern?

JAG1, NOTCH2, AD

85% of infants born with this syndrome have neonatal cholestasis, with 95% also being born with a heart defect such as pulmonic stenosis or tetralogy of fallot.

Alagille syndrome

This syndrome has a pseudogene, NOTCH2NLR that often interferes with molecular analysis. What is the de novo rate of the syndrome?

60%

What is the gene and inheritance pattern for spinocerebellar ataxia type 1?

ATXN1, AD

This ataxia condition commonly onsets in the 30-40s, with death occuring after 10-30 years. Juvenile onset (<13) is also possible, and most Juvenile cases pass before the age of 16. Symptoms include ataxia, bulbar dysfunction (impairment of the lower cranial nerves that control swallowing, speaking, chewing, and breathing), and muscle atrophy.

Spinocerebellar ataxia type 1

What is the trinculeotide repeat that is expanded in ATXN1? What is considered abnormal?

CAG, 39+ repeats

CAG expansions in ATXN1 are more likely when (maternally/paternally) transmitted?

Paternally

Friedrich’s ataxia gene and inheritance pattern

FXN, AR

Hypertrophic cardiomyopathy is a common symptom in this ataxia condition that typically onsets in early adulthood (M= 10-15years of age)

Friedrich’s ataxia

What trinucleotide is expanded in FXN in Friedrich’s ataxia?

GAA

You are evaluating for a multisystem non-motile ciliopathy that is known to be heterogenous. This condition’s main symptoms include, retinal cone-rod dystorphy, postaxial polydactyly, obesity, and urogenital issues. What is the name of the condition?

Bardet-Biedl

What is the main symptom of Factor V Leiden? Associated gene?

Thrombosis, F5

Hemophilia A gene and inheritance pattern

F8, XLR