Changing facial phenotype in Cohen syndrome: towards clues for an earlier diagnosis

Eur J Hum Genet. 2013 Jul;21(7):736-42. doi: 10.1038/ejhg.2012.251. Epub 2012 Nov 28.

Abstract

Cohen syndrome (CS) is a rare autosomal recessive condition caused by mutations and/or large rearrangements in the VPS13B gene. CS clinical features, including developmental delay, the typical facial gestalt, chorioretinal dystrophy (CRD) and neutropenia, are well described. CS diagnosis is generally raised after school age, when visual disturbances lead to CRD diagnosis and to VPS13B gene testing. This relatively late diagnosis precludes accurate genetic counselling. The aim of this study was to analyse the evolution of CS facial features in the early period of life, particularly before school age (6 years), to find clues for an earlier diagnosis. Photographs of 17 patients with molecularly confirmed CS were analysed, from birth to preschool age. By comparing their facial phenotype when growing, we show that there are no special facial characteristics before 1 year. However, between 2 and 6 years, CS children already share common facial features such as a short neck, a square face with micrognathia and full cheeks, a hypotonic facial appearance, epicanthic folds, long ears with an everted upper part of the auricle and/or a prominent lobe, a relatively short philtrum, a small and open mouth with downturned corners, a thick lower lip and abnormal eye shapes. These early transient facial features evolve to typical CS facial features with aging. These observations emphasize the importance of ophthalmological tests and neutrophil count in children in preschool age presenting with developmental delay, hypotonia and the facial features we described here, for an earlier CS diagnosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Abnormalities, Multiple
  • Child
  • Child, Preschool
  • Developmental Disabilities / diagnosis
  • Developmental Disabilities / genetics
  • Developmental Disabilities / physiopathology
  • Early Diagnosis
  • Face / physiopathology*
  • Female
  • Fingers / abnormalities
  • Fingers / physiopathology
  • Humans
  • Intellectual Disability / diagnosis*
  • Intellectual Disability / genetics*
  • Intellectual Disability / physiopathology
  • Male
  • Microcephaly / diagnosis*
  • Microcephaly / genetics*
  • Microcephaly / physiopathology
  • Muscle Hypotonia / diagnosis*
  • Muscle Hypotonia / genetics*
  • Muscle Hypotonia / physiopathology
  • Mutation
  • Myopia / diagnosis*
  • Myopia / genetics*
  • Myopia / physiopathology
  • Obesity / diagnosis*
  • Obesity / genetics*
  • Obesity / physiopathology
  • Phenotype
  • Retinal Degeneration
  • Vesicular Transport Proteins / genetics*

Substances

  • VPS13B protein, human
  • Vesicular Transport Proteins

Supplementary concepts

  • Cohen syndrome