Molecular Diagnosis of Syndromic or Isolated Severe Intellectual Disability Using Whole Exome Sequencing : a Pilot Study
Molecular Diagnosis of Syndromic or Isolated Severe Intellectual Disability Using Whole Exome Sequencing : a Pilot Study
Evaluation of diagnostic whole exome sequencing in patients with syndromic or isolated severe
 intellectual disability without a molecular diagnostic, with suspected autosomal recessive
 inheritance, allowing accurate genetic counseling in this high risk of recurrence group of
 diseases
Inclusion Criteria:

 -  Clinical diagnosis of syndromic or isolated severe intellectual disability (IQ <50)
 without a molecular diagnosis

 -  Recurrence in siblings (multiplex families) suggesting autosomal recessive inheritance
 (with or without parental consanguinity) or sporadic cases from a consanguineous union

 -  Conventional genetic tests performed (including array-CGH) and MRI/CT-scan available

 -  DNA samples from parents and from both unaffected or affected siblings available, for
 parental segregation and confirmation of candidate variations identified.

 -  Availability of a signed informed consent

 -  To be affiliated or beneficiary of French social security/healthcare system

 Exclusion Criteria:

 -  Parents in the exclusion period of another study or as provided by the national
 register of volunteers

 -  High-probability diagnostic hypothesis for which a molecular test is available at
 lower cost than exome sequencing