Chromosomal‐array analysis reveals partial 11q duplication and partial 12p deletion in a mildly affected case

Abstract

Partial trisomy 11q is a rare syndrome and may be observed due to an intra-chromosomal duplication or an inter-chromosomal insertion. The deletions of the short arm of chromosome 12 are also uncommon structural aberrations. Only a small fraction of structural chromosome anomalies are related to the unbalanced progeny of balanced translocation carrier parents. We here report on a 10-month-old baby boy who shows a very mild phenotype related to unique chromosomal abnormality, partial trisomy of 11q, and partial monosomy of 12p, due to the maternal balanced reciprocal translocation (11;12). The proband showed a 49.64 Mb duplication of 11q14.1-q25 and 0.44 Mb deletion of 12p13.33 in chromosomal array analysis. Since it is known that the duplications may cause a milder phenotype than deletions. Dysmorphic facial features, minor cardiac anomalies, respiratory distress, central nervous system anomalies, and psychomotor delay observed in the patient was similar to the reported pure 11q duplication cases, while behavioral problems observed in pure monosomy 12p cases could not be evaluated due to the young age of the patient. Phenotype-genotype correlation will be discussed in view of all the reported pure partial 11q trisomies and pure partial 12p deletion cases.

A rare case of trisomy 11q23.3-11q25 and trisomy 22q11.1-22q11.21

“…Unbalanced chromosomal abnormalities are uncommon structural aberrations that occur frequently due to unbalanced meiotic segregation in the gametes of balanced translocation carriers (Pfeiffer and Schütz, 1993;Yelavarthi and Zunich, 2004;Tuğ et al, 2014). Here, we described a maternal proband who carried a balanced reciprocal translocation between chromosomes 11 and 22, and who gave birth to an unbalanced progeny.…”

Clinical and molecular evaluations of siblings with “pure” 11q23.3-qter trisomy or reciprocal monosomy due to a familial translocation t (10;11) (q26;q23.3)

“…Zhao et al, reported a 5-years-old girl with an inverted duplication of 11q13-qter as the only cytogenetic abnormality detected in the patient [ 12 ]. Recently, a 17 month old boy with “pure” 11q23.1-qter trisomy [ 17 ] and a 10-month-old boy with 11q14.1-qter trisomy and minimal involvement of 12p [ 22 ] were reported. Among the above five cases, only the most recent case by Tug et al was molecularly evaluated by chromosomal microarray, where the exact range of 11q duplication and the size and gene content of 12p monosomy were determined.…”

“…None of the cases reported by Pihko et al was pure trisomy 11qter. Since then, more than thirty 11q distal trisomy (involving telomere) cases other than the Emanuel syndrome have been reported in the literature [ 4 - 22 ] and the Decipher database (case# 282318; 251238; 258577; 251238 and 253250) ( https://decipher.sanger.ac.uk ). Common clinical features of these cases are similar to that of Emanuel syndrome, which include pre- and post-natal growth retardation, psychomotor delay, mild to moderate intellectual disability, distinctive craniofacial abnormalities such as microcephaly, brachycephaly, a short nose; low-set ears, high arched/cleft palate, preauricular pits or tags, micrognathia and long philtrum.…”

“…These cases provided opportunity for analyzing the clinical consequence of trisomy 11qter. Currently, only five such cases have been previous reported [ 5 , 8 , 12 , 17 , 22 ]. Here we presented the molecular and clinical features of three siblings with the smallest “pure” 11qter trisomy.…”