[Congenital insensitivity to pain caused by a novel SCN9A-genotype]

Congenital insensitivity to pain (CIP) refers to a group of extremely rare genetic disorders characterized by a lifelong inability to sense pain. Interestingly, in most cases, other neurological functions remain essentially intact. Here, we present the long-term follow-up of a 73 year old Icelandic male who, along with his two brothers, were diagnosed with CIP in childhood. This report details his clinical history, neurological findings, and whole genome sequencing results, which confirm and elucidate the genetic basis of his condition, explained by compound heterozygosity of two rare mutations in SCN9A. One has previously been described in CIP (p.Lys1659Ter). The other is a novel CIP variant consisting of a rare deletion (c.417-15_4174-14delAT) that causes exon 23 to be spliced out, and loss of 18 amino acids from the protein.