Sarcoglycanopathy: Clinical and histochemical characteristics in 66 patients

Background: Sarcoglycanopathies are a group or autosomal recessive muscular dystrophies designated as α, β, γ, or δ sarcogycanopathy.
Materials and Methods: It is a retrospective analysis of case series.
Results: Sixty six patients immunohistochemically confirmed to have sarcoglycan deficiency were included in the analysis. The study period extended from 1997-2008. The male to female ratio was 1.5:1. Mean age at the onset of muscle complaints was 6.2±3.7 years (range 1-18). Mean age at evaluation was 10.0±4.8 years (range 3-31). Mean duration of illness was 47.02±44.80 months (range 3-325). Onset in the first decade was seen in 59 (89.4%) and 25 (42.4%) of these had onset before five years of age. The remaining seven (10.6%) had onset in second decade and none after 20 years of age. Consanguinity was present in 54 (81.8%). In 34 of 66 cases only a-SG was carried out and this had shown total absence of staining in all fibers. In the remaining 32 cases where the entire panel was performed, absence of all sarcoglycans was noted in 10 (15.1%), isolated a-SG deficiency in 7 (10.6%), isolated b-SG deficiency in 6 (9.1%), and isolated g-SG deficiency in 3 (4.5%). Combination deficiency was also observed: absence of α and β (n=4), β and γ (n=2), and α and γ (n=1).
Conclusions: Our series was a large series and with predominantly pediatric age group. Sarcoglycanopathy should be particularly suspected in a child born to consanguineous parents and who presents with proximal muscle weakness and calf hypertrophy, elevated CK level, and myopathic pattern on EMG.