SNOMEDCT: 764944006; ORPHA: 98893; DO: 0110634;
Cytogenetic location: 1q42 Genomic coordinates (GRCh38): 1:223,900,001-236,400,000
| Location | Phenotype |
Phenotype MIM number |
Inheritance |
Phenotype mapping key |
|---|---|---|---|---|
| 1q42 | Muscular dystrophy, congenital, 1B | 604801 | Autosomal recessive | 2 |
Muntoni et al. (1998) described a form of congenital muscular dystrophy characterized by proximal muscle weakness, muscle hypertrophy, and early respiratory failure in a consanguineous family from the United Arab Emirates. The pattern of inheritance was clearly autosomal recessive. The muscle hypertrophy was generalized, and there was rigidity of the spine and contractures of the Achilles tendons. Severe diaphragmatic involvement was responsible for the early respiratory failure. Intellect and the results of brain imaging were normal. Serum creatine kinase levels were grossly elevated, and muscle biopsy samples showed dystrophic changes. Affected individuals were demonstrated to have a deficiency of laminin alpha-2 (LAMA2; 156225) in muscle, but this appeared to be a secondary phenomenon, since linkage to the LAMA2 locus on 6q22-q23 was excluded.
Brockington et al. (2000) performed genomewide linkage analysis on the family reported by Muntoni et al. (1998) and found that all 4 affected children showed an identical homozygous region on 1q42, spanning 6 to 15 cM. In a second German family with 2 affected children having similar clinical and histopathologic features, the data were consistent with linkage to the same locus. The cumulative lod score was 3.57 at theta = 0.00 at marker D1S213.
Brockington et al. (2000) proposed calling this disorder congenital muscular dystrophy 1B, or CMD1B. However, since CMD1B has been used to represent dilated cardiomyopathy 1B (600884), the disorder is referred to here as MDC1B.
Brockington, M., Sewry, C. A., Herrmann, R., Naom, I., Dearlove, A., Rhodes, M., Topaloglu, H., Dubowitz, V., Voit, T., Muntoni, F. Assignment of a form of congenital muscular dystrophy with secondary merosin deficiency to chromosome 1q42. Am. J. Hum. Genet. 66: 428-435, 2000. [PubMed: 10677302] [Full Text: https://doi.org/10.1086/302775]
Muntoni, F., Taylor, J., Sewry, C. A., Naom, I., Dubowitz, V. An early onset muscular dystrophy with diaphragmatic involvement, early respiratory failure and secondary alpha-2 laminin deficiency unlinked to the LAMA2 locus on 6q22. Europ. J. Paediat. Neurol. 1: 19-26, 1998.