[Analysis of genetic variant in a child with concomitant spinal muscular atrophy and Citrin protein deficiency].

OBJECTIVE: To explore the genetic basis for a child with concomitant spinal muscular atrophy (SMA) and Citrin protein deficiency. METHODS: The child was subjected to whole exome sequencing by using target sequence capture high-throughput sequencing. Candidate variants were verified by Sanger sequencing. The SMN genes of the patient were also analyzed through multiplex ligation-dependent probe amplification (MLPA). RESULTS: The patient was found to carry homozygous deletion of exons 7 and 8 of the SMN1 gene, for which his parents were both carriers. The patient also carried compound heterozygous variants c.1737G>A and IVS16ins3kbof the SLA25A13 gene, in addition with compound heterozygous variants c.948G>A and c.2693T>C of the POLG gene, for which his parents were carriers, too. CONCLUSION: Variants of the SLC25A13 gene probably underlay the deficiency of Citrin protein, which may lead to neonatal intrahepatic cholestasis (NICCD). The patient also had SMA. The compound heterozygous variants c.948G>A and c.2693T>C of the POLG gene are likely to cause mitochondrial DNA deletion syndrome type 4A, though other types of mitochondrial disease cannot be excluded.