title: Intragenic rearrangements in LARGE and POMGNT1 genes in severe dystroglycanopathies.
abstract: Dystroglycanopathies are a heterogeneous group of muscular dystrophies with autosomal recessive inheritance characterized by abnormal glycosylation of alpha-dystroglycan. The most severe phenotypes are Walker-Warburg Syndrome (WWS) and muscle-eye-brain disease (MEB) presenting with lissencephaly type II (LIS II) and in which muscular dystrophy is associated with mental retardation and eye abnormalities. To date, six distinct genes, POMT1, POMT2, POMGNT1, FKTN, FKRP, LARGE and recently in one case DPM3, have been shown to be involved in dystroglycanopathies. Genomic sequencing alone is still frequently used for diagnosis purpose, not allowing detection of intragenic rearrangements at the heterozygous state contrarily to RNA analysis, quantitative PCR and CGH array analysis. These latter methods enabled us to identify four new intragenic rearrangements in the LARGE gene in three fetuses with WWS, born to two unrelated families: deletion of exons 9-10 and duplication of introns 1-4 for the first family and deletion of exons 4 and 7 for the second one; and a deletion of the last six exons of the POMGNT1 gene in two unrelated MEB patients. Genomic dosage studies using emerging tools such as CGH array should be included in routine molecular analysis of dystroglycanopathies, not only for the screening of the LARGE gene in which this kind of mutation seems to be more frequent than point mutations, but also for the other involved genes, especially in severe clinical cases.
authors: APHP, Hôpital Bichat-Claude Bernard, Biochimie, 46 rue Henri Huchard, Paris Cedex 18, France. sandrine.vuillaumier@bch.aphp.fr
authors: S
authors: S
authors: Vuillaumier-Barrot
authors: C
authors: C
authors: Bouchet-Seraphin
authors: M
authors: M
authors: Chelbi
authors: A
authors: A
authors: Eude-Caye
authors: E
authors: E
authors: Charluteau
authors: C
authors: C
authors: Besson
authors: S
authors: S
authors: Quentin
authors: L
authors: L
authors: Devisme
authors: C
authors: C
authors: Le Bizec
authors: P
authors: P
authors: Landrieu
authors: A
authors: A
authors: Goldenberg
authors: K
authors: K
authors: Maincent
authors: P
authors: P
authors: Loget
authors: O
authors: O
authors: Boute
authors: B
authors: B
authors: Gilbert-Dussardier
authors: F
authors: F
authors: Encha-Razavi
authors: M
authors: M
authors: Gonzales
authors: B
authors: B
authors: Grandchamp
authors: N
authors: N
authors: Seta
mesh_terms: D002648:Child; D003241:Consanguinity; D004252:DNA Mutational Analysis; D005091:Exons / Q000235:genetics; D005333:Fetus; D020440:Gene Duplication / Q000235:genetics*; D006801:Humans; D008297:Male; D018895:Microsatellite Repeats / Q000235:genetics; D017351:N-Acetylglucosaminyltransferases / Q000235:genetics*; D010641:Phenotype; D017423:Sequence Analysis, RNA; D017384:Sequence Deletion / Q000235:genetics*; D058494:Walker-Warburg Syndrome / Q000235:genetics* / Q000503:physiopathology
chemical_list: C117674:LARGE1 protein, human; D017351:N-Acetylglucosaminyltransferases; C443106:protein O-mannose beta-1,2-N-acetylglucosaminyltransferase