Muscular dystrophies — Flashcards

Flashcard 1: Duchenne muscular dystrophy classically presents with the _____ sign, in which a patient uses their upper extremities to help stand up

Answer: Gower

Flashcard 2: Which glycogen storage disorder is associated with cardiomegaly? _____

Answer: Pompe disease

Flashcard 3: What trinucleotide repeat disorder is associated with autism?_____

Answer: Fragile X syndrome

Flashcard 4: Duchenne muscular dystrophy presents with weakness in the _____ muscles and progresses superiorly

Answer: pelvic girdle

Flashcard 5: Enzyme deficiency and inheritance of Hunter syndrome?

Answer: Enzyme deficiency: Iduronate sulfatase Inheritance: X-linked recessive (XR)

Extra: - Accumulation of heparan sulfate and dermatan sulfate. - Clinical features: Developmental delay, gargoylism, airway obstruction, hepatosplenomegaly. - Distinctive features: Aggressive behavior, NO corneal clouding (unlike Hurler syndrome).

Flashcard 6: What is the enzyme deficiency in Hurler's syndrome?

Answer: Deficiency of α-L-iduronidase

Extra: • Inheritance: Autosomal Recessive (AR) • Accumulation of: Heparan sulfate and Dermatan sulfate • Clinical Features: Developmental delay, gargoylism, airway obstruction, corneal clouding, hepatosplenomegaly.

Flashcard 7: What manifestation of 22q11 deletion syndrome define velocardiofacial syndrome?

Answer: cardiac, palate, facial defects

Flashcard 8: What is the genetic defect in Williams syndrome?

Answer: 7q11.23 microdeletion (including elastin gene)

Extra: Characteristics of Williams Syndrome: - Elfin facies - Intellectual disability (mild retardation) - Hyper-verbal / Cocktail party personality (hyper-friendly) - Cardiovascular problems: Supravalvular aortic stenosis (SVAS) - Idiopathic hypercalcemia in infancy

Flashcard 9: Clinical features and genetic defect in Prader-Willi syndrome?

Answer: Mental retardation, hyperphagia, obesity, hypogonadism, hypotonia

Extra: Paternal deletion or mutation on chromosome 15 (15q11-q13). Since the maternal copy is normally silenced (imprinted), the loss of the paternal allele leads to disease.

Flashcard 10: Is there male-to-male transmission in X-linked recessive disorders?

Answer: No male-to-male transmission (only through females) :: Can affected males transmit the disease to their sons?

Extra: X-linked recessive inheritance: - More males affected than females. - No male-to-male transmission (males pass Y to sons). - All daughters of an affected male are obligate carriers. - Skips generations (transmission via carrier females).