Isolated Dandy-Walker malformation associated with brain stem dysgenesis in male sibs.

We describe two brothers with isolated Dandy-Walker malformation (DWM). Interestingly, brain stem dysgenesis and abnormal gyral pattern were also observed in the sibs. They presented with psychomotor retardation and macrocrania. Both suffered from hypotonia with brisk deep tendon reflexes and ataxic gait. They had bilateral optic atrophy and the visual evoked potentials documented prolonged latencies. Further, motor and sensory conduction velocities were normal. Chromosomal examinations for the sibs and their parents showed normal results. The majority of cases are sporadic but rare reports of recurrence in siblings exist. The parents' consanguinity and the recurrence in a subsequent pregnancy suggest an autosomal recessive inheritance pattern. Our report adds more weight that brain stem dysgenesis could be associated with DWM, increasing the spectrum of heterogeneity of this malformation.