Last modified: 2018-09-09
Abstract
Case 1 was 14 day old female baby born of third degree consanguineous marriage presented with decreased movements, weak cry. On antenatal ultrasonography, there was blake pouch cyst at 20 weeks gestation which disappeared at 24 weeks. She had hypotonia, bilateral ankle and toe contractures. There was increased creatine kinase (CK) level, normal metabolic work up, electromyography (EMG) and nerve conduction study(NCV). Genetic analysis showed a homozygous pathogenic mutation in exon 23 of the LAMA2 gene.
Case 2 was 5 year old female baby born of third degree consanguineous marriage. There was increased CK level, MRI T2 hyperintensities in both frontopariatal white matter with delayed myelination, normal EMG, NCV, metabolic work up and muscle biopsy showed merosin deficiency with partial loss of dystrophin C terminal. Child had delayed motor development and increased respiratory infections since 6 months of age with contractures of both knees and ankles. There were no seizures or cardiac involvement. Patient expired at five and half years due to respiratory complications. Genetic analysis could not be done. Exome analysis of each parent showed similar heterozygote pathogenic carrier mutation in exon 13 of LAMA2 gene.
Discussion-
Cerebellar cysts are known in CMD but prenatal blake pouch cyst disappearing later has not been reported earlier. Partial deficiency of merosin due to mutations in LAMA2 and secondary deficiency due to changes in other proteins has to be differentiated from other CMDs. Genotype and phenotype correlation is also discussed.