Genetic Disorders and Biochemical Pathology — Flashcards

Flashcard 201: _____ is characterized by mutations in the ABCG5 and ABCG8 genes.

Answer: Sitosterolemia

Extra: Sitosterolemia (phytosterolemia) is an autosomal recessive disorder resulting in hyperabsorption and decreased biliary excretion of plant sterols (e.g., sitosterol, campesterol). It is caused by mutations in the **ABCG5** and **ABCG8** genes, which encode sterolin-1 and sterolin-2 (ATP-binding cassette transporters). Clinical features include: - Tendon and tuberous xanthomas - Premature atherosclerosis and coronary artery disease - Hemolytic anemia and large platelets (sometimes)

Flashcard 202: HHH syndrome is caused due to the deficiency of the ornithine _____.

Answer: transporter

Flashcard 203: _____ syndrome is characterized by a partial deficiency of HGPRT and has no neurological complications

Answer: Kelley-Seegmiller

Flashcard 204: _____ porphyria is associated with increased levels of uroporphyrin 1.

Answer: Congenital erythropoietic

Flashcard 205: Fabry s disease is inherited as _____ disorder.

Answer: X-linked recessive

Flashcard 206: _____ is characterized by mutations in the ABCG5 and ABCG8.

Answer: Sitosterolemia

Extra: Sitosterolemia (phytosterolemia) is an autosomal recessive disorder leading to increased levels of plant sterols in the blood and tissues. It results from mutations in either ABCG5 or ABCG8, which form the heterodimeric transporter (sterolin) that normally excretes these sterols into the gut and bile. Clinical features include xanthomas and premature atherosclerosis.

Flashcard 207: MELAS is due to defects in mitochondrial proteins like ETC complex _____ or complex _____.

Answer: I; IV

Flashcard 208: A _____ syndrome is a rare inherited absence of peroxisomes (not a mitochondrial disorder).

Answer: cerebrohepatorenal

Flashcard 209: _____ syndrome / MPS _____ is caused by the deficiency of _____.

Answer: Maroteaux-Lamy syndrome; VI; Arylsulfatase B (N-acetylgalactosamine-4-sulfatase)