Pontocerebellar hypoplasia type 11: Does the genetic defect determine timing of cerebellar pathology?

Pontocerebellar hypoplasia type 11: Does the genetic defect determine timing of cerebellar pathology? Eur J Med Genet. 2020 Apr 28;:103938 Authors: Laugwitz L, Buchert R, Groeschel S, Riess A, Grimmel M, Beck-Wödl S, Sturm M, Gohla G, Döbler-Neumann M, Krägeloh-Mann I, Haack TB Abstract Pontocerebellar hypoplasia (PCH) comprises a clinically and genetically heterogeneous group of disorders characterized by hypoplasia and degeneration of the cerebellum and ventral pons. To date at least 18 different clinical subtypes of PCH associated with pathogenic variants in 19 different genes have been described. Only recently, bi-allelic variants in TBC1D23 have been reported as the underlying molecular defect in seven index cases with a suspected non-degenerative form of PCH, PCH type 11 (PCH11). We used exome sequencing to investigate an individual with global developmental delay, ataxia, seizures, and progressive PCH. Brain volume was evaluated over a disease course of 14 years using volumetric magnetic resonance imaging (MRI). Volume alterations were compared to age-matched controls as well as data from children with PCH2. We identified a homozygous frameshift variant in exon 9 of 18 of TBC1D23 predicting a loss of protein function. Brain morphometry revealed a pattern of pontine, brain stem, and supratentorial volume loss similar to PCH2 patients although less pronounced. Intriguingly, cerebral MRI findings at the age of 1 and 15 years c...
Source: European Journal of Medical Genetics - Category: Genetics & Stem Cells Authors: Tags: Eur J Med Genet Source Type: research