Identification of a large homozygous SPG21 deletion in a Chinese patient with Mast syndrome

A37‐year old man presented a slight delay in early developmental milestones, cognitive decline, difficulty walking, cerebellar signs and extrapyramidal signs. Brain magnetic resonance imaging (MRI) showed a thin corpus callosum, cerebral atrophy, non‐specific white‐matter hyperintensity, and cerebellar atrophy. The genetic test revealed a putative homozygous deletion in SPG21 from exon 3 through exon 7, which was further validated by long‐range primer‐walking PCR. This is the first report of Chinese patient with Mast syndrome carrying a large homozygous SPG21 deletion.