No abstract

Homozygous or compound heterozygous mutations in the GJC2 gene, encoding the gap junction protein connexin47 (Cx47), cause the autosomal recessive hypomyelinating Pelizaeus-Merzbacher-like disease (PMLD1, MIM# 608804). Although clinical and neuroradiological findings resemble those of the classic Pelizaeus-Merzbacher disease, PMLD patients usually show a greater level of cognitive and motor functions. Unpredictably a homozygous missense GJC2 mutation (p.Glu260Lys) was found in a patient presenting with a very severe clinical picture characterised by congenital nystagmus and severe neurological impairment. Also magnetic resonance imaging was unusually severe, showing an abnormal supra-and infratentorial white matter involvement extending to the spinal cord. The novel p.Glu260Lys (c.778G4A) mutation, occurring in a highly conserved motif (SRPTEK) of the Cx47 extracellular loop-2 domain, was predicted, by modelling analysis, to break a 'salt bridge network', crucial for a proper connexin-connexin interaction to form a connexon, thus hampering the correct formation of the connexon pore. The same structural analysis, extended to the previously reported missense mutations, predicted that most changes were expected to have less severe impact on protein functions, correlating with the mild PMLD1 form of the patients. Our study expands the spectrum of PMLD1 and provides evidence that the extremely severe clinical and neuroradiological PMLD1 form of our patient likely correlates with the predicted impairment of gap junction channel assembly resulting from the detrimental effect of the new p.Glu260Lys mutant allele on Cx47 protein.

Shapiro Syndrome is a rare entity defined by the triad of recurrent spontaneous hypothermia, hyperhidrosis, and agenesis of the corpus callosum. Fewer than 100 cases have been reported so far and there are only few cases without a complete agenesis of corpus callosum ("Shapiro Syndrome Variant"). In this article, we report the clinical, electroencephalographic, and neuroimaging data of a patient with early-onset Shapiro Syndrome Variant. The case study describes a 4-year-old patient with episodes characterized by generalized hyperhidrosis, hypotonia, impaired consciousness, and hypothermia with onset before the first year of age. We captured an event during which the EEG showed rhythmic low- to medium-voltage theta waves without clear epileptiform activity. Brain MRI was normal and Shapiro Syndrome Variant was hypothesized. We started treatment with pizotifen, and after 2 years, the patient showed a reduction in frequency and duration of episodes. Shapiro Syndrome, although rare, should be considered in the differential diagnosis in patients with neurovegetative symptoms which suggest epileptic attacks at first. Our case is of particular interest to specialists because Shapiro SyndromeVariant is a rare syndrome and our patient had a very early onset of symptoms.In addition, we report our experience with pizotifen therapy, which produced a good response.