Genetics

Question 1

Triad of congenital cataracts and severe hypotonia in a male neonate with a family history of severe renal disease suggests the diagnosis of?

What is the inheritance pattern? Gene involved?

Answer 1

Oculocerebrorenal syndrome (Lowe syndrome)

X-linked

OCRL gene

Question 2

GALT mutation associated with?

Answer 2

Mutation in GALT causes a deficiency in the activity of the enzyme galactose-1-phosphate uridyltransferase, the cause of classic galactosemia

Question 3

COL1A1 mutation associated with?

Answer 3

Osteogenesis imperfecta is caused by mutations in COL1A1, coding for type 1 procollagen. Affected infants have increased bone fragility and risk for fractures and some may have blue sclera, but cataracts are not found

Question 4

GLA mutation associated with?

Inheritance pattern?

Answer 4

Mutation in GLA is found in patients with Fabry disease. This is an X-linked lysosomal storage disease caused by deficiency in the enzyme α-galactosidase A leading to accumulation of glycophospholipid in tissues

Question 5

Male patient with cardiac, renal, and neurologic involvement — what is the likely dx?

Answer 5

Fabry disease

Ophthalmologic manifestations are common in Fabry disease as a result of progressive deposition of glycosphingolipids in different structures of the eye. The corneal opacities that occur are called cornea verticillata, cream-colored opacities distributed in a vortex pattern. They are considered the most reliable ophthalmologic finding in Fabry disease, and present later in life.