Authors:
Fehr S; Wilson M; Downs J; Williams S; Murgia A; Sartori S; … De Klerk N; Leonard H; et al.
Authors notes:
European Journal of Human Genetics. 2013;21(3):266-273
Keywords:
CDKL5, dysmorphology, natural history, phenotype, Rett syndrome
Abstract:
The clinical understanding of the CDKL5 disorder remains limited, with most information being derived from small patient groups seen at individual centres.
This study uses a large international data collection to describe the clinical profile of the CDKL5 disorder and compare with Rett syndrome (RTT).
Most individuals with CDKL5 mutations had severe developmental delay from birth, seizure onset before the age of 3 months and similar non-dysmorphic features.
Less than one-quarter met the criteria for early-onset seizure variant RTT. Seizures and sleep disturbances were more common than in those with MECP2 mutations whereas features of regression and spinal curvature were less common.
The CDKL5 disorder presents with a distinct clinical profile and a subtle facial, limb and hand phenotype that may assist in differentiation from other early-onset encephalopathies.
Although mutations in the CDKL5 gene have been described in association with the early-onset variant of RTT, in our study the majority did not meet these criteria.
Therefore, the CDKL5 disorder should be considered separate to RTT, rather than another variant.