Occasionally recessive mutations are identified: a recent publication described a distinct neonatal epileptic encephalopathy (MIM 615905) caused by autosomal recessive mutations in the SLC13A5 gene.
Screening of 68 additional unrelated individuals with early-onset epileptic encephalopathy for SLC13A5 mutations led to identification of one additional subject with compound heterozygous mutations of SLC13A5 and a similar clinical presentation as the index subjects.
We conclude that SLC13A5 is the second major gene associated with the clinical diagnosis of KTZS, characterised by neonatal epileptic encephalopathy and hypoplastic AI.