Subject(s)
Motor Skills , Muscular Atrophy, Spinal/genetics , Muscular Atrophy, Spinal/physiopathology , Adolescent , Adult , Age of Onset , Child , Child, Preschool , Female , Humans , Infant , Male , Middle Aged , Muscular Atrophy, Spinal/classification , Survival of Motor Neuron 2 Protein/genetics , Young AdultABSTRACT
Spinal muscular atrophy with respiratory distress type 1 is an autosomal recessive disorder with early respiratory difficulties, distal muscle weakness, and contractures leading to foot deformities as the most striking clinical symptoms. Mutations of the gene encoding the immunoglobulin heavy chain µ-binding protein 2, mapped on chromosome 11q13, are the cause of the disease. We present the clinical and mutational characteristics of ten patients in the Netherlands who showed considerable clinical variability; they carried six novel mutations, including a deletion of exon 2. However, there were no clear phenotype-genotype correlations.
Subject(s)
Muscle Weakness/genetics , Muscular Atrophy, Spinal/genetics , Mutation/genetics , Respiratory Distress Syndrome, Newborn/genetics , Spinal Muscular Atrophies of Childhood/genetics , Child, Preschool , Chromosome Mapping , Female , Genetic Predisposition to Disease/genetics , Humans , Infant , Male , Muscular Atrophy, Spinal/diagnosis , Netherlands , Respiratory Distress Syndrome, Newborn/diagnosis , Spinal Muscular Atrophies of Childhood/diagnosis , Transcription Factors/geneticsABSTRACT
We identified de novo truncating mutations in ARID1B in three individuals with Coffin-Siris syndrome (CSS) by exome sequencing. Array-based copy-number variation (CNV) analysis in 2,000 individuals with intellectual disability revealed deletions encompassing ARID1B in 3 subjects with phenotypes partially overlapping that of CSS. Taken together with published data, these results indicate that haploinsufficiency of the ARID1B gene, which encodes an epigenetic modifier of chromatin structure, is an important cause of CSS and is potentially a common cause of intellectual disability and speech impairment.
Subject(s)
Abnormalities, Multiple/genetics , Chromatin Assembly and Disassembly/genetics , DNA-Binding Proteins/genetics , Hand Deformities, Congenital/genetics , Intellectual Disability/genetics , Micrognathism/genetics , Transcription Factors/genetics , Child , Child, Preschool , DNA Copy Number Variations , Face/abnormalities , Female , Humans , Male , Middle Aged , Mutation , Neck/abnormalities , Sequence Deletion , Speech Disorders/geneticsABSTRACT
Failure to thrive, feeding difficulties, variable forms of infantile epilepsy or psychomotor developmental delay and hypotonia were the most frequent clinical disease presentations in eight children with combined oxidative phosphorylation enzyme complex deficiencies carrying mutations in the polymerase gamma (POLG1) gene. Five out of eight patients developed severe liver dysfunction during the course of the disease. Three of these patients fulfilled the disease criteria for Alpers syndrome. Most children showed deficiencies of respiratory chain enzyme complexes I and III, in combination with complex II, complex IV and/or PDHc in muscle, whereas in fibroblasts normal enzyme activities were measured. All children carried homozygous or compound heterozygous mutations in the POLG1 gene, including two novel mutations in association with mtDNA depletion. Conclusion We suggest performing POLG1 mutation analysis in children with combined oxidative phosphorylation deficiencies in muscle, even if the clinical picture is not Alpers syndrome.
