del (9p) syndrome: Proposed behavior phenotype

Abstract

Over recent years interest in the study of behavior phenotypes has gained increasing momentum. We present three white female patients, age respectively 9 years 9 months, 14 years 6 months and 18 years at the time of the last observation, seen because of developmental delay/mental retardation, seizures and learning disabilities. Cytogenetic analysis showed a de novo deletion of the short arm of chromosome 9 in all three, with the breakpoint being located at band 9p22. Although several studies have described the somatic phenotype, analytical evaluation of verbal and non-verbal cognitive functions are lacking. Our patients received a detailed neuropsychological and linguistic evaluation that showed a particular behavior profile, in the context of mental retardation of variable degree. On selective tests there was a marked deficit in visuo-praxic and visuo-spatial skills associated with memory disturbance. Visuo-motor integration abilities [VMI; Beery, 1997] and visuo-perceptual and visuo-spatial abilities [Benton line orientation test, 1992] seemed particularly impaired, both in relation to verbal mental age (vocabulary and grammatical production/comprehension) and to some non-verbal competencies [Benton face recognition test, 1992]. The profile shows advanced performances in face recognition. In addition, there is also a dissociation between verbal and visuo-spatial short term memory. This behavior phenotype is similar to that of Williams syndrome (WS) individuals. Our patients also showed some unusual within-domain dissociations regarding linguistic abilities. To better demonstrate similarities and differences between the behavior phenotypes of the del (9p22) syndrome and WS, we studied three IQ-gender-matched WS subjects. The comparison between the cognitive phenotypes of the two syndromes shows similarities in neuropsychological pattern. We hypothesize that there is a gene within the 9p22 region responsible for the neuropsychological profile described here.

Clinical and cytogenetic characterization of 13 Dutch patients with deletion 9p syndrome: Delineation of the critical region for a consensus phenotype

“…Learning disabilities in our study group varied from mild to severe. In a review by Chilosi et al [2001], describing phenotypic behavior in three patients with a 9p deletion, it was reported that language acquisition and language comprehension were delayed, but that eventually spontaneous language production was rather fluent and, typically the patients spoke in an adult-like way. The language development of the patients in the present study confirmed these findings, with the typical adult-like way of speaking reported by most parents.…”

“…In 1999, Christ et al [1999] reduced the critical region for a consensus phenotype consisting of mental retardation, trigonocephaly, small palpebral fissures, flat nasal bridge with anteverted nostrils, long philtrum, and micro/retrognathia in 24 patients to a $8 Mb interval on chromosome 9p22. Overall, however, no clear genotype-phenotype correlations have been reported, except for sex reversal [Calvari et al, 2000;Muroya et al, 2000;Chilosi et al, 2001].…”

“…Male and female patients are usually equally affected. IQ scores in 14 patients have been reported to range from 33 to 73 [Huret et al, 1988] and speech development is delayed in most cases [Chilosi et al, 2001].…”

Does Spatial Locative Comprehension Predict Landmark-Based Navigation?

“…Test for Reception of Grammar (TROG: [ 40 ]; Italian version: [ 41 ]). We tested verbal comprehension of spatial locatives using the TROG, which assesses grammatical comprehension from age 4 to adulthood.…”

Osteogenic differentiation of human mesenchymal stem cells on poly(ethylene glycol)‐variant biomaterials

“…Male and female patients are usually equally affected. IQ scores in 14 patients have been reported to range from 33 to 73 [Huret et al, 1988] and speech development is delayed in most cases [Chilosi et al, 2001].…”