We report seven affected individuals from six families with a recurrent, de novo variant in the ARPC4 gene (c.472C>T p.Arg158Cys (GenBank: NM_005718.4)). Core features in affected individuals include ...microcephaly, mild motor delays, and significant speech impairment. ARPC4 is a core subunit of the actin-related protein (ARP2/3) complex, which catalyzes the formation of F-actin networks. We show that the recurrent ARPC4 missense change is associated with a decreased amount of F-actin in cells from two affected individuals. Taken together, our results implicate heterozygous ARPC4 missense variants as a cause of neurodevelopmental disorders and microcephaly.
We report a neurodevelopmental disorder with microcephaly in seven affected individuals with the same de novo variant in the ARPC4 gene. The recurrent variant in ARPC4, a subunit of the complex that catalyzes F-actin network formation, is associated with decreased F-actin in cells from affected individuals.
In the field of dysmorphology, achondroplasia is a well-known disorder. Sinus pericranii (SP), however, is not. The latter condition is a rare vascular malformation characterized by abnormal ...connections between the intracranial and the extracranial venous drainage pathways. The etiology of SP remains unclear, and yet, these defects can be present at birth, develop spontaneously later, or evolve following head trauma. Here, we report on a 2-year-old male with achondroplasia, SP, and craniocervical junction stenosis. The latter two defects required surgical correction. SP is an underappreciated malformation that we propose may be induced by increased intracranial pressure. This case appears to be the first report of this condition in achondroplasia.
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