engleski

Clinical phenotype of muscle-eye-brain disease (MEB) without mutations in POMGnT1 and FKRP genes: some other form of glycosylation disorder?

Our patient is the second child of young unrelated parents. Family history is unremarkable. He was born at term after uneventful pregnancy. During the neonatal period horizontal nystagmus and microphtalmia of the right eye were noticed. Ophtalmological examination of the right eye revealed retinal detachment, vitreous organisation and microphtalmia, while on the left eye there was retinal rarefaction with focal proliferation of pigment epithelium and opacities in anterior vitreous. At the age of 2.5 months more thorough clinical evaluation was performed. The child had truncal hypotonia, lower limb hypertonus, reduced spontaneous movements, flexion contractures of hips and knees, delay in neuromotor development and dysmorphic features (dolychochephaly, high palate, depressed nasal bridge, low set ears and poorly shaped right ear). Deep tendon reflexes on lower limbs couldn’ t be elicited. Interesting distinction which we couldn’ t connect to other features was xerosis with regional ichthyosiform skin changes. Biochemical investigation showed permanently very high creatine kinase (the highest value was 9366 U/L). Syalotransferin isoelectrofocusing was normal. Results of pathohystological analysis and electromyoneurography pointed to muscular dystrophy. Brain MR revealed cerebellar cortical dysplasia and subcortical cerebellar cysts, hypoplasia of vermis and pons, polymicrogyria (most pronounced in the frontal region) with granular and irregular cortex – findings typical for MEB. Visual evoked potentials with electroretinography detected severe neuronal impartment of left visual pathway and no response on the right side. At the age of 15 months (last clinical evaluation) child presented with growth retardation, truncal and upper limb girdle hypotonia and severe psychomotor delay (without head control, unable to sit, with reduced spontaneous movements and relatively good social contact). Skin changes remaind as previously. Due to typical clinical presentation (with the exception of skin changes), structural brain abnormalities and course of the disease we thought that child suffered from muscle-eye-brain disease. Unexpectedly, molecular analysis of POMGnT1 and FKRP genes didn’ t reveal mutations. Could this child suffer from some other form of congenital glycosylation disorder? We consider further diagnostic procedures.

muscle-eye-brain disease

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