Paracentric inversion of chromosome 2 associated with cryptic duplication of 2q14 and deletion of 2q37 in a patient with autism.
We describe a patient with autism and a paracentric inversion of chromosome 2q14.2q37.3, with a concurrent duplication of the proximal breakpoint at 2q14.1q14.2 and a deletion of the distal breakpoint at 2q37.3. The abnormality was derived from his mother with a balanced paracentric inversion. The inversion in the child appeared to be cytogenetically balanced but subtelomere FISH revealed a cryptic deletion at the 2q37.3 breakpoint. High-resolution single nucleotide polymorphism array confirmed the presence of a 3.5 Mb deletion that extended to the telomere, and showed a 4.2 Mb duplication at 2q14.1q14.2. FISH studies using a 2q14.2 probe showed that the duplicated segment was located at the telomeric end of chromosome 2q. This recombinant probably resulted from breakage of a dicentric chromosome. The child had autism, mental retardation, speech and language delay, hyperactivity, growth retardation with growth hormone deficiency, insulin-dependent diabetes, and mild facial dysmorphism. Most of these features have been previously described in individuals with simple terminal deletion of 2q37. Pure duplications of the proximal chromosome 2q are rare and no specific syndrome has been defined yet, so the contribution of the 2q14.1q14.2 duplication to the phenotype of the patient is unknown. These findings underscore the need to explore apparently balanced chromosomal rearrangements inherited from a phenotypically normal parent in subjects with autism and/or developmental delay. In addition, they provide further evidence indicating that chromosome 2q terminal deletions are among the most frequently reported cytogenetic abnormalities in individuals with autism.
Devillard
Françoise
F
Département de Génétique et Procréation, CHU de Grenoble, Grenoble, France.
Guinchat
Vincent
V
Moreno-De-Luca
Daniel
D
Tabet
Anne-Claude
AC
Gruchy
Nicolas
N
Guillem
Pascale
P
Nguyen Morel
Marie-Ange
MA
Leporrier
Nathalie
N
Leboyer
Marion
M
Jouk
Pierre-Simon
PS
Lespinasse
James
J
Betancur
Catalina
C
D000293:Adolescent; D001321:Autistic Disorder / Q000235:genetics*; D002869:Chromosome Aberrations; D007446:Chromosome Inversion; D002889:Chromosomes, Human, Pair 2 / Q000235:genetics*; D002658:Developmental Disabilities / Q000235:genetics; D005190:Family; D020440:Gene Duplication; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008607:Intellectual Disability / Q000235:genetics; D008297:Male; D020641:Polymorphism, Single Nucleotide; D017384:Sequence Deletion