Interstitial deletion 2p11.2–p12: Report of a patient with mental retardation and review of the literature

Abstract

Deletions of chromosome bands 2p11.2 and 2p12 are rare, and only six patients have been reported to date. Here, we report on a 5-year-old girl with an 11.4 Mb interstitial deletion of chromosome bands 2p11.2-p12 and the characterization of this deletion by high-resolution array CGH. The patient presented with mental retardation, microcephaly and short stature. Facial features included broad nasal bridge, frontal bossing and mild dolichocephaly. Phenotypic comparison with previously published patients failed to reveal a consistent clinical pattern apart from developmental delay/mental retardation, which is probably due to different sizes and/or positions of the individual deletions. Among the 40 known genes deleted in our patient is REEP1, haploinsufficiency of which causes autosomal dominant spastic paraplegia type 31 (SPG31, OMIM 610250). Additional patients with well-characterized deletions within 2p11.2 and 2p12 will be needed to determine the role of individual genes for the clinical manifestations.

Interstitial deletion 2p11.2–p12: Further delineation

“…In three patients including a pair of sibs molecular characterization of breakpoints of the 2p11.2-12 deletion has been reported [Barber et al, 2005;Tzschach et al, 2009]. The deleted segments were 11.4 Mb [Tzschach et al, 2009], 10.4 Mb (present case) and 7.5 Mb [Barber et al, 2005] in size.…”

“…3). Only the patient with the largest deletion had microcephaly [Tzschach et al, 2009]. The minimal region for microcephaly is the region between 87.2 and 91.5 Mb, located in band 2p11.2.…”

“…The deleted segments were 11.4 Mb [Tzschach et al, 2009], 10.4 Mb (present case) and 7.5 Mb [Barber et al, 2005] in size. The largest deletion extended about 4 Mb more proximally into the gene rich 2p11.2 band than the other two (Fig.…”

A recurrent deletion syndrome at chromosome bands 2p11.2-2p12 flanked by segmental duplications at the breakpoints and including REEP1

“…MIM 613564). [9][10][11][12] All show mild-to-moderate intellectual disability, a very happy disposition, speech delay, delayed motor development and minor facial anomalies such as high forehead, broad nasal bridge and large low set ears (Table 1). Despite the very large size of the del(2)(p11.2p12), the clinical phenotype is relatively mild when compared generally with similar-sized deletions reported in literature.…”

“…13,14 HSP-related features were seen in patient 1, the previous patient with the 9.4-Mbp deletion 2 and other patients with REEP1 deletions. 10,11 The age distribution for SPG31 shows a bimodal pattern of o20 and 430 years of age 13,14 leaving a possibility that HSP is not yet manifest in patient 1. Figure 1 Interstitial deletion 2p11.2-2p12 in patients 1 and 2 as identified by high-resolution Cytoscan HD array.…”