[P2-41] Distinct MRI features in a patient with novel RARS2 mutations
Pontocerebellar hypoplasia type 6(PCH6) was a rare autosomal recessive disease due to mutations in RARS2, and 23 cases were reported so far.
We described a case with PCH6 caused by novel RARS2 mutations with distinct MRI features. 23 published cases were reviewed.
The clinical features of the present patient were suggestive of PCH6, with early onset epilepsy, feeding problem, severe developmental delay, microcephaly, hearing loss and hyperlactacidemia. Early onset hypotonia (43.48%), epileptic seizures (34.78%), encephalopathy (26.08%) and feeding difficulties (17.39%) were common initial symptoms of PCH6 in the reported 23 cases. During disease progression, patients presented refractory epileptic seizures (94.12%), feeding problem (60.87%), severe developmental delay (100%), microcephaly (88.89%) and hyperlactacidemia (76.47%). According to available MRI data from 20 reported cases with PCH6, 16 of the characteristic finding in MRI was pontocerebellar dysplasia or progressive cerebral/pontocerebellar atrophy, and none of them with basal ganglia involvement. Distinctive MRI features were identified in the present case, including pontocerebellar preservation after 1 year of age, as well as high DWI signal suggested of intracellular edema in cerebellar hemispheres, basal ganglia, thalamus and corpus callosum. Novel compound heterozygous mutations in RARS2, c.1718C>T(p.Thr573Ile) and c.991A>G(p.Ile331Val) were identified.
The present case enriched both the phenotypic and genotypic spectrum of the RARS2 mutations.
We described a case with PCH6 caused by novel RARS2 mutations with distinct MRI features. 23 published cases were reviewed.
The clinical features of the present patient were suggestive of PCH6, with early onset epilepsy, feeding problem, severe developmental delay, microcephaly, hearing loss and hyperlactacidemia. Early onset hypotonia (43.48%), epileptic seizures (34.78%), encephalopathy (26.08%) and feeding difficulties (17.39%) were common initial symptoms of PCH6 in the reported 23 cases. During disease progression, patients presented refractory epileptic seizures (94.12%), feeding problem (60.87%), severe developmental delay (100%), microcephaly (88.89%) and hyperlactacidemia (76.47%). According to available MRI data from 20 reported cases with PCH6, 16 of the characteristic finding in MRI was pontocerebellar dysplasia or progressive cerebral/pontocerebellar atrophy, and none of them with basal ganglia involvement. Distinctive MRI features were identified in the present case, including pontocerebellar preservation after 1 year of age, as well as high DWI signal suggested of intracellular edema in cerebellar hemispheres, basal ganglia, thalamus and corpus callosum. Novel compound heterozygous mutations in RARS2, c.1718C>T(p.Thr573Ile) and c.991A>G(p.Ile331Val) were identified.
The present case enriched both the phenotypic and genotypic spectrum of the RARS2 mutations.