The Primordial Dwarfisms: Diagnosis, Identification of the Molecular Basis of Seckel Syndrome and Microcephalic Osteodysplastic Primordial Dwarfism Type II

Inclusion Criteria: Patients aged from 2 months to 50 years must present all of the following criteria: * Symmetrical intrauterine growth restriction (IUGR) \< - 2 DS, Birth size \<-2 DS and Cranial perimeter of birth \<-2 DS * Postnatal growth restriction (size \<-4DS) * Microcephaly \<-4DS * Clinical Diagnosis of Seckel Syndrome or Microcephalic osteodysplastic primordial dwarfism type II (MOPDII) by a geneticist * Having given free and informed consent Exclusion Criteria: * Refutation of the diagnosis * Parents' refusal to participate in genetic studies once the diagnosis of SCKL or MOPDII has been establish for the patient (major or minor) * Allergy to gadolinium, contraindicating the realization of an Angio-MRI * Absence of affiliation to a social security scheme or Universal Health Coverage.