Partial trisomy 18q in a newborn with typical 18 trisomy phenotype

Abstract

This paper describes a case of partial trisomy of almost the entire long arm of chromosome 18 in a newborn with classic trisomy-18 phenotype, resulting from a de novo unbalanced 181/21p translocation: karyotype: 46,XX,-21,t(18;21)(18qter leads to 18q11 ::21p12 leads to 21qter). A review of the other reported cases of partial trisomy 18 suggests that a critical segment in chromosome 18, corresponding to bands q11-q12, might be responsible for most of the signs of trisomy 18, including failure to thrive and early death.

Partial Duplication of 18q Including a Distal Critical Region for Edwards Syndrome in a Patient with Normal Phenotype and Oligoasthenospermia: Case Report

“…Partial duplication of the long arm of chromosome 18 involving only the distal critical region has also been dePresent work Boghosian-Sell et al, 1994Matsuoka et al, 1981Mueke et al, 1982Fryns et al, 1978Turleau and De Grouchy, 1977 Fig. 3.…”

“…In that time, several authors have attempted to construct a phenotype map of chromosome 18 for duplications of different portions of the chromosome aimed to identify possible critical regions [Turleau and De Grouchy, 1977;Fryns et al, 1978;Matsuoka et al, 1981;Mueke et al, 1982;Boghosian-Sell et al, 1994] ( fig. 3 ).…”

Edward’s Syndrome: Analysis of Own Clinical Observations

“…Клінічні прояви синдрому у дітей досить ва-ріабельні [3,8], однак найбільш типовими феноти-повими ознаками є: мала вага при народженні (близько 2177-2340 г у доношеному терміні), долі-хоцефалічна форма голови, "пташиний" профіль обличчя, аномалії кінцівок (деформації кистей, стоп). Характерні мікроцефалія, виступаюча по-тилиця, деформовані та низько посаджені вуха, мікрогнатія, короткі очні щілини, птоз.…”

Combined deletion 18q22.2 and duplication/triplication 18q22.1 causes microcephaly, mental retardation and leukencephalopathy

“…The classic Edwards syndrome with mental and developmental delay, growth deficiency, craniofacial dysmorphism, clenched hands with overlapping digits and internal organ malformation is associated with a duplication of the entire chromosome 18 (Binkert et al, 1990). However, partial trisomy 18 with mild to severe phenotypes of Edwards syndrome have also been reported (Boghosian-Sell et al, 1994;Fryns et al, 1978;Matsuoka et al, 1981;Neu et al, 1976). Attempts to identify critical regions remain inconclusive.…”