Pure interstitial dup(6)(q22.31q22.31) - a case report

'Pure' interstitial duplication of chr6q is rare. The varying size of duplication encompassing 6q22.31 is associated with the expressivity of dysmorphism and autism. Here, we report a unique case with facial dysmorphism, developmental delay, complex neurological impairment and spasticity unrelated to autism. Genetic analysis by aCGH exhibited a 627-971 kb dup(6)(q22.31q22.31) encompassing TRDN and NKAIN2 genes. The presence of the duplication was confirmed by quantitative PCR in the proband and phenotypically normal parents. With the current techniques, we cannot exclude presence of a deleterious homozygous point mutation in the proband where each copy would have been inherited from both parents.