Download Genetic analysis of myotonic dystrophy patients

Abstract book of 2nd Iranian annual neurogenetic Congress
Genetic analysis of myotonic dystrophy patients
Mohammad Hossein Sanati*, Omid Aryani, Massoud Houshmand
Myotonic dystrophy (DM), one of the most common forms of muscular dystrophy, is an inherited disorder
of the muscles and other body systems. DM is a progressive genetic disorder with a triplet repeat autosomal
mutation that affects an estimated 1 in 8000 people. Myotonic dystrophy type 1, also known as Steinert's
disease, and type 2 caused by mutation in DMPK and CNBP genes, respectively. In each case, an unstable
region in the gene forms by abnormal repeating of a short segment of DNA. DM1 is caused by an expanded
and unstable (CTG)n trinucleotide repeat, located in the 3' untranslated region of the dystrophia myotonicaprotein kinase (DMPK) gene on chromosome 19. The mutated gene produces an altered version of messenger
RNA, which is a molecular blueprint of the gene that is normally used for protein production. The abnormal
messenger RNA forms clumps inside the cell that interfere with the production of many proteins. The signs
and symptoms of myotonic dystrophy are the result of the prevented cells in muscles and other tissues from
functioning normally. Myotonic dystrophy type 2 (DM2), also known as proximal myotonic myopathy
(PROMM), is a milder form of myotonic dystrophy where transient muscle pain is the most common complaint.
Additional forms (DM3, DM4) have been suggested, as a small number of individuals have been seen who
have the characteristic symptoms of myotonic dystrophy, but who do not have the genetic mutations which
cause these disroders. Considerable debate exists as to whether these individuals truly represent a new form
of myotonic dystrophy or whether they simply present unique diagnostic challenges.We have tested the CTG
trinucleotide repeat of the DMPK gene in our patients sample by PCR and PAGE electrophoresis methods.
* Mohammad Hossein Sanati, Ph.D
Molecular Genetic Diagnosis Lab, Special Medical Center, Tehran, Iran.
P.O.Box: 14155-6343, Tel: +98 21 44580390 / E.mail: [email protected]
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