10p11.2 to 10q11.2 is a yet unreported region leading to unbalanced chromosomal abnormalities without phenotypic consequences

Abstract

Directly transmitted unbalanced chromosomal abnormalities (UBCA) or euchromatic variants (EV) were recently reported for >50 euchromatic regions of almost all human autosomes. UBCA and EV are comprised of a few megabases of DNA, and carriers are in many cases clinically healthy. Here we report on partial trisomies of chromosome 10 within the pericentromeric region which were detected by standard G banding. Those were referred for further delineation of the size of these duplicated regions for molecular cytogenetics and/or array-CGH. Partial trisomies of chromosome 10 in the pericentromeric region were identified prenatally in seven cases. A maximum of three copies of the region from 10p12.1 to 10q11.22 was observed in all cases without apparent clinical abnormalities. The imbalances were either caused by a direct duplication in one familial case or by de novo small supernumerary marker chromosomes (sSMC). Thus, we report a yet unrecognized chromosomal region subject to UBCA detected in seven unrelated cases. To the best of our knowledge, this is the first report of a UBCA in the pericentromeric region of chromosome 10 that is not correlated with any clinical consequences.

The clinical utility of molecular karyotyping for neurocognitive phenotypes in a consanguineous population

“…For instance, a mother with normal cognition-patient 13DG1188-was found to have a Chr10q11.22 duplication, which we found among several patients and parents with both normal and abnormal cognition, which may explain the controversy surrounding the pathogenicity of this CNV in the literature. 18 Another interesting finding was a 7q31.1 deletion that encompasses IMMP2L, a gene that has been reported in association with ADHD, 19 autism, 20 and Tourette syndrome. 21 This deletion was maternally inherited in a patient with cognitive impairment (08DG00266) from an unaffected mother (08DG00268).…”

Diagnostic Yield of Chromosomal Microarray Analysis in an Autism Primary Care Practice: Which Guidelines to Implement?

“…Some of these variants are quite unlikely to contribute to ASD susceptibility. These may include benign copy number variants that have been previously described in the general population, such as the gain on chromosome 10p11.23 (Liehr et al 2009). Other variants are known risk factors for other disorders, including individuals who are carriers of recessive disorders, such as the losses on chromosomes 2q35 and 10p13.…”

Three-Year Follow-Up of a Prenatally Ascertained Apparently Non-Mosaic sSMC(10): Delineation of a Non-Critical Region

“…A non-critical region, ranging from 34.72 to 44.51 Mb (UCSC hg19, 2009) has been proposed based on cases with mosaic sSMC(10) [Liehr et al, 2009]. Only one apparently non-mosaic case of sSMC(10) was described in a phenotypically normal fetus but without postnatal follow-up.…”