Cohen syndrome in two patients from China

Background: Cohen syndrome (CS; OMIM 216550) is a rare syndrome with evident clinical heterogeneity. The diverse phenotype comprises early-onset hypotonia and developmental delays, intellectual disabilities, microcephaly, hypermobile joints, neutropenia, myopia, and characteristic facial features. The disease is rarely reported. Vacuolar Protein Sorting 13 Homolog B (VPS13B; OMIM 607817) is the only causative gene of CS.

Methods: Blood samples sourced from both siblings and parents were sent to identify mutations by trio-WES, and changes in the patient's condition were understood through consultation data and follow-up.

Results: We reported two siblings affected by developmental delay, microcephaly, intellectual disability, and facial features. The siblings' WES detected compound heterozygous variants in the exon region of VPS13B (NM_017890): c.9337A>T and c.8551A>C.

Conclusion: Two individuals were diagnosed with CS by genetic testing and clinical features. In addition, we conduct a brief review of the reports on the Chinese population with CS and reinforce the understanding of the correlation between genotype-phenotype.