Cerebellar Cysts and Dysplasias: More Diagnoses to Consider

This 2.5-year-old boy presented with developmental delay from early infancy and tremulousness while reaching for objects. Examination revealed microcephaly (46 cm, −3.57 z score), generalized hypotonia, hyporeflexia, limb dysmetria, and gait ataxia, but no muscular weakness. On ophthalmologic assessment, he had high myopia bilaterally. Magnetic resonance imaging revealed cerebellar dysplasia and multiple cortical-subcortical cysts in the cerebellum (Fig). A next-generation whole-exome sequencing revealed a homozygous, pathogenic frameshift variant,Chr18(GRCh37):g.6997844_6997845delNM_005559.3:c.4702_4703delp.(Leu1568Glyfs*2)Exon 33, confirming the diagnosis of LAMA 1-associated Poretti–Boltshauser syndrome. The child began rehabilitation, and corrective glasses were given for myopia.