Síndrome de Coffin-Lowry: Presentación de un caso y Guías Diagnóstico-evolutivas y Anticipatorias

Abstract

Coffi n-Lowry syndrome (CLS) is a syndromic form of X-linked mental retardation, which is characterized in male patients by psychomotor delay and growth retardation, large soft hands with distally tapering fi ngers, and other skeletal anomalies. Characteristic features change and become more marked with age but are already apparent by the second year of life. About 20% of patients have paroxysmal drop attacks in response to unexpected noises or tactile stimuli. Sensorineural deafness has been reported, rarely with late onset. Female heterozygotes commonly express the condition to a less severe degree, but psychotic behaviour may also be an occasional manifestation. CLS is caused by mutations in RSK2 gene, located at Xp22.2, which encodes a growth factor-regulated serine-threonine protein kinase in the RASMAPK signalling pathway. Mutations are extremely heterogeneous, and a high rate of new mutations and germinal mosaicism are also reported. Gene expression and protein synthesis, mediated by the transcription factor CREB, play an important role in memory and learning. RSK2 actives CREB by phosphorylation and is also required for osteoblasts differentiation and function, mediated by phosphorylation ATF4. This suggests that loss of RSK2 function may contribute to the cognitive defi cits and skeletal anomalies in CLS patients. A 10-year-old patient with typical phenotype is described here. He and his mother have a new mutation (c.407C>T) not previously described. We review clinical, etiologic, diagnostic and molecular aspects of CLS.