French clinicians and biologists report the observations of three families of North African origin who were diagnosed with deficiency of SMVT, a sodium-dependent multi-vitamin transporter:
- the clinical picture was one of severe axon-demyelinating neuropathy, appearing early (in childhood) and often complicated by optic atrophy, and recurrent episodes of incoercible vomiting, suggesting dysautonomia,
- High-throughput sequencing in these three families identified the same pathological homozygous variant in the SLC5A6 gene encoding SMVT.
Beyond the probable founder effect, the authors stress the need for early diagnosis, which is the only guarantee of the efficacy of multi-vitamin replacement therapy.
