title: Mutation studies in X-linked myotubular myopathy in three Indian families.
abstract: Congenital myopathies are a group of genetic disorders characterized by generalised muscle hypotonia and weakness of varying severity. They are distinct entities and do not include muscular dystrophies, metabolic myopathies and mitochondrial disorders. Myotubular myopathy is a rare sub type within this group of disorders. Clinical differentiation of the various types is difficult and requires muscle biopsy with histopathological and immunohistochemical studies for specific diagnosis. Gene studies are a prerequisite for genetic counseling adn prenatal diagnosis. Here presented three cases of X-linked myotubular myopathy in three Indian families where the diagnosis was established by mutation analysis in the MTM1 gene in all, and supported his histopathology in two. All three families had history of previous male neonatal deaths with similar complaints. Molecular analysis revealed hemizygous mutations in the MTM1 gene including c.1261-10A>G in case, 1, c.70C>T (R24X) in case 2, and a previously unreported mutation, c.924_926delCTT(p. F308del), in case 3. Genetic counseling was performed regarding the X-linked inheritance, their 50% risk of recurrence in boys in subsequent pregnancies, and a feasibility of prenatal diagnosis. This is the first report of cases of X-linked myotubular myopathy from India.
authors.affiliation: Center of Medical Genetics, Department of Neonatology, Sir Ganga Ram Hospital, Rajinder Nagar, New Delhi, India. Bijarnia@gmail.com
authors.forename: Sunita
authors.initials: S
authors.lastname: Bijarnia
authors.forename: Ratna D
authors.initials: RD
authors.lastname: Puri
authors.forename: Monika
authors.initials: M
authors.lastname: Jain
authors.forename: Neelam
authors.initials: N
authors.lastname: Kler
authors.forename: Subimal
authors.initials: S
authors.lastname: Roy
authors.forename: J Andoni
authors.initials: JA
authors.lastname: Urtizberea
authors.forename: Valerie
authors.initials: V
authors.lastname: Biancalana
authors.forename: I C
authors.initials: IC
authors.lastname: Verma
mesh_terms: D040181:Genetic Diseases, X-Linked / Q000235:genetics*; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D018482:Muscle, Skeletal / Q000473:pathology; D009154:Mutation; D020914:Myopathies, Structural, Congenital / Q000175:diagnosis* / Q000235:genetics* / Q000473:pathology; D054558:Protein Tyrosine Phosphatases, Non-Receptor / Q000235:genetics*
chemical_list: D054558:Protein Tyrosine Phosphatases, Non-Receptor; C099588:myotubularin