Ullrich congenital muscular dystrophy and Bethlem myopathy: clinical and genetic heterogeneity.
Ullrich congenital muscular dystrophy (UCMD), due to mutations in the collagen VI genes, is an autosomal recessive form of CMD, commonly associated with distal joints hyperlaxity and severe course. A mild or moderate involvement can be occasionally observed.


OBJECTIVE
To evaluate the clinical picture of CMD patients with Ullrich phenotype who presented decreased or absent collagen VI immunoreactivity on muscular biopsy.


RESULTS
Among 60 patients with CMD, two had no expression of collagen V and their clinical involvement was essentially different: the first (3 years of follow-up) has mild motor difficulty; the second (8 years of follow-up) never acquired walking and depends on ventilatory support. A molecular study, performed by Pan et al. at the Thomas Jefferson University, demonstrated in the first a known mutation of Bethlem myopathy in COL6A1 and in the second the first dominantly acting mutation in UCMD and the first in COL6A1, previously associated only to Bethlem myopathy, with benign course and dominant inheritance.


CONCLUSIONS
Bethlem myopathy should be considered in the differential diagnosis of UCMD, even in patients without fingers contractures; overlap between Ullrich and Bethlem phenotypes can be supposed.
Reed
Umbertina Conti
UC
Departamento de Neurologia, Faculdade de Medicina, Universidade de São Paulo, São Paulo, Brasil. ucontireed@hcnet.usp.br
Ferreira
Lucio Gobbo
LG
Liu
Enna Cristina
EC
Resende
Maria Bernadete Dutra
MB
Carvalho
Mary Souza
MS
Marie
Suely Kazue
SK
Scaff
Milberto
M
D000293:Adolescent; D001706:Biopsy; D002648:Child; D002675:Child, Preschool; D024142:Collagen Type VI / Q000172:deficiency* / Q000235:genetics; D003937:Diagnosis, Differential; D005500:Follow-Up Studies; D018740:Genetic Heterogeneity; D006801:Humans; D007150:Immunohistochemistry; D007593:Joint Instability / Q000235:genetics / Q000473:pathology; D008297:Male; D009136:Muscular Dystrophies / Q000151:congenital / Q000235:genetics* / Q000473:pathology; D010641:Phenotype
D024142:Collagen Type VI