[A clinical, neurophysiological and molecular study of 12 patients from 4 families with spinal and bulbar muscular atrophy]. / L'amyotrophie bulbaire et spinale liée au chromosome X: une étude clinique, neurophysiologique et moléculaire de 12 patients issus de 4 familles.

INTRODUCTION: Spinal and bulbar muscular atrophy (SBMA) is an X-linked, late-onset neuro-endocrine disorder resulting from an expansion of a CAG repeat in the androgen receptor gene. Material and method. We report the detailed phenotypic study in a series of 12 SBMA patients evaluated in four kindreds. RESULTS: Clinical phenotypic spectrum varied considerably, ranging from childhood-onset weakness and atrophy mimicking limb-girdle myopathy in patients with 53 CAG repeats to isolated hyperCKemia in an adult with 42 CAG repeats. All male patients had gynecomastia. Two female carriers presented with paresthesias and hand action tremor. Homozygous deletions of SMN1 and SMN2 genes were not found in any patients. CONCLUSION: This report demonstrates that SBMA may present with a wider clinical spectrum than previously described and suggests that clinical phenotype severity in SBMA is partially linked to the number of CAG repeats. It also suggests that SMN1 and SMN2 genes do not act as modifying genes in SBMA.

A family with early-onset and rapidly progressive X-linked spinal and bulbar muscular atrophy.

Spinal and bulbar muscular atrophy (SBMA) is an X-linked, late-onset neuroendocrine disorder resulting from an expansion of a CAG repeat in the androgen receptor gene. Reported here is a detailed phenotypic study in a series of seven patients from the same family with SBMA with 50 to 54 CAG repeats, juvenile onset (mean age at onset 13 years [8 to 15 years]), and rapid progression leading to compromised ambulation in the mid-20s.