Intellectual, adaptive and behavioural characteristics in four patients with 18p deletion syndrome

Abstract

Background The association of behavioural phenotype assessment with cytogenomic characterisation may provide a better comprehension of genotype–phenotype correlations in syndromes caused by chromosomal abnormalities, such as 18p deletion syndrome. Method We report on four Brazilian patients with 18p deletion syndrome characterised by cytogenomic techniques and detailed neuropsychological evaluation. Intellectual, adaptive and behavioural characteristics were assessed through the Wechsler's Scales, the Vineland‐II Scale and the Child Behaviour Checklist, respectively. Socio‐economic measures including main caretaker educational level and family income as defined by Brazilian criteria for social class classification were also collected to evaluate a possible contribution of environmental factors in neurocognitive variability. Results Two out of four patients showed intellectual disability (IQ < 70). Wechsler's scale results suggest that in our sample, interpretation of social situations based on observation of non‐verbal behaviour constitute a cognitive strength while judgement of social rules and language skills associated with word knowledge and verbal fluency may be a cognitive weakness. Concerning adaptive behaviour, motor and socialisation domains showed to better develop than communication and daily living skills on the Vineland‐II Scale. Only one patient presented internalising behavioural problems based on the Child Behaviour Checklist. Our results also suggested that socio‐economic status may contribute to overall patient development. Conclusion Our results suggest that some 18p deletion syndrome patients may present average intellectual performance and that the segment deletion size and some families' socio‐economic conditions may influence cognitive development.

18p Deletion Syndrome Originating from Rare Unbalanced Whole-Arm Translocation between Chromosomes 13 and 18: A Case Report and Literature Review

“…Therefore, this case supports the severity of the phenotypic manifestation associated with functional gene loss at the 18p breakpoints [ 11 , 12 , 14 ]. Other published cases have identified an absence of specific functional genes in critical regions, causing clinical manifestations of 18p- syndrome that are consistent to some degree with our findings; these include a round face in the most distal part of 18p and short stature and seizures in 18p11.32 [ 1 , 10 , 15 ]. In addition, it is possible that the mild phenotypic abnormalities seen in our case might have resulted from the preserved segment of p11.1, whereas deletions in the centromeric region of 18p (between p11.1 and p11.21) are associated with typical facial dysmorphism and moderate to severe intellectual disabilities [ 12 ].…”

“…However, since not all those with 18p- syndrome resulting from unbalanced translocation (13;18) have the same phenotype, other genetic factors should be considered. Moreover, considering the upper-middle socio-economic status and early support consisting of special school attendance in this case, environmental factors could have played an additional role in the patient’s favorable outcome as well [ 15 ]. Therefore, identifying the etiology of the untypical and varied clinical phenotypes of this syndrome is still challenging.…”

Developmental Speech Delay and Autism in an Infant With Chromosome 18p Deletion: Prioritizing Candidate Processes

“…Распространенность синдрома оценивается как 1:50 000 новорожденных детей, соотношение полов составляет 2:3 (М:Ж) [2,3]. Большинство случаев (более 75%) являются результатом делеции de novo.…”

Chromosome 18p deletion syndrome (18p-) in children: the value of cytogenetic and molecular cytogenetic diagnosis

“…Все больные значительно отстают в психомоторном развитии, страдает речь (афазия или дисфазия, фразовая речь часто отсутствует до 7-9 лет). Встречаются грубые пороки головного мозга при первом варианте заболевания (аринэнцэфалия, прозэнцефалические пороки, гипоплазия гипофизагипопитуитаризм, циклопия, цебоцефалия) [3,4,5]. У этих пациентов снижена продолжительность жизни.…”

“…При цитогенетическом анализе делеция (потеря хромосомного материала короткого плеча хромосомы 18) выявлена, как с точками разрыва, локализованными в районе 18р11.1 с участием околоцентромерного гетерохроматина, так и в участках 18р11.2 -18р11. 3 Рис. 3.…”