A 32-year-old woman presents with progressive difficulty releasing objects after gripping and daytime somnolence. Vital signs: BP 118/76, HR 82, RR 16, Temp 37°C, SpO2 98%. Examination reveals frontal balding, bilateral cataracts, and delayed muscle relaxation after handgrip test. Serum creatine kinase is mildly elevated at 450 U/L. She denies weakness. Her newborn son is hypotonic and weak with poor feeding. Expansion of which of the following trinucleotide repeats is most likely present in this family?
- A)CAA
- B)CGG
- C)CAG
- D)GAA
- E)CTGGABARITO
Explicação
Myotonic dystrophy type 1 is caused by CTG repeat expansion and shows anticipation, often with more severe congenital disease in the next generation. The adult phenotype includes myotonia, cataracts, frontal balding, and endocrine abnormalities. The maternal h... Ver explicação completa e trilha adaptativa →