De Novo Mutations of the CCNK gene cause a Neurodevelopmental Disorder

De Novo Mutations of CCNK Cause a Syndromic Neurodevelopmental Disorder with Distinctive Facial Dysmorphism Cytogenetic location 14q32.2

Chromosome 14 ideogram

Neurodevelopment is a complex process that requires the coordination and regulation of several cellular activities. This regulation is maintained through precise control of when genes are transcribed. Gene transcription is the process of encoding the information from genes into proteins, which can be used to carry out these cellular activities. Disruption of the neurodevelopmental process can lead to developmental delay (DD) or intellectual disability (ID). Human Cyclin K (CCNK) is a protein that is involved in this transcriptional control. Prior to this study, there was no association between the CCNK gene and a neurodevelopmental disorder.

This article describes three individuals with de novo (occurring spontaneously, and not inherited from parents) deletions in 14q32.2 area, involving the CCNK gene. Each of these patients revealed severe DD and ID, and dysmorphic features, including a high hairline, hypertelorism (abnormally wide-set eyes), thin eyebrows, low-set ears, broad nose, thin upper lip, and narrow jaw. There is no known association between DD/ID symptoms and several additional genes missing in 3 patients with deletions in this area. The fourth patient who had a missense mutation in the CCNK gene had similar clinical manifestations. These data allowed the conclusion that the CCNK gene is a main factor causing DD, ID and dysmorphic features in this condition.

The comparison with previously reported patients with deletions of this area of 14q32 showed that all these persons share developmental delay, intellectual disability and facial dysmorphism.

Fan, et al. “De Novo Mutations of CCNK Cause a Syndromic Neurodevelopmental Disorder with Distinctive Facial Dysmorphism”. The American Journal of Human Genetics. 2018, v. 103, 448-455.

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