An interstitial deletion of chromosome 7 at band q21: A case report and review

Abstract

We report on a girl with moderate developmental delay and mild dysmorphic features. Cytogenetic investigations revealed a de novo interstitial deletion at the proximal dark band on the long arm of chromosome 7 (7q21.1-q21.3) in all analyzed G-banded metaphases of lymphocytes and fibroblasts. Fluorescence in situ hybridization (FISH) and molecular studies defined the breakpoints at 7q21.11 and 7q21.3 on the paternal chromosome 7, with the proximal deletion breakpoint between the elastin gene (localized at 7q11.23) and D7S2517, and the distal breakpoint between D7S652 and the COL1A2 gene (localized at 7q21.3-q22.1). Deletions of interstitial segments at the proximal long arm of chromosome 7 at q21 are relatively rare. The karyotype-phenotype correlation of these patients is reviewed and discussed. The clinical findings of patients with a deletion at 7q21 significantly overlap with those of patients with maternal uniparental disomy of chromosome 7 (matUPD(7)) and Silver-Russell syndrome (SRS, OMIM 180860). Therefore, 7q21 might be considered a candidate chromosomal region for matUPD(7) and SRS.

Chromosome abnormalities identified in 457 spontaneous abortions and their histopathological findings

“…Intermediate interstitial deletion of chromosome 7 spanning from q22 to q31 bands is rare and causes multiple congenital malformations in the affected children (26,27). Only a few rare prenatally detected cases presenting with fetal growth retardation and ultrasonographic findings such as cranial malformations, syndactyly in the lower extremities, renal pelvic dilatation,…”

Characterization of a 16 Mb interstitial chromosome 7q21 deletion by tiling path array CGH

“…More than 20 patients with cytogenetically visible interstitial deletions of 7q21-q22 [Fukushima et al, 2003;Courtens et al, 2005;Manguoglu et al, 2005], and one patient with a microdeletion in 7q21.3 [Wieland et al, 2004] have been reported to date. Among other clinical problems (mental retardation, short stature, microcephaly, hearing loss), split hand/split foot malformation was a common feature in patients with deletions of subbands 7q21.3 and 7q22.1.…”

Intermediate Interstitial Deletion of Chromosome 7q Detected by First-Trimester Down’s Syndrome Screening

“…Moreover, cardiomegaly was also detected on sonographic evaluation. Although cardiac anomalies are not commonly associated with interstitial chromosome 7q deletion, postnatally detected ventricular septal defects and pulmonary stenosis were reported [6,12,15] . We were unable to attribute a specific cause for the cardiomegaly due to the limitations of sonographic resolution and lack of postmortem assessment (deferred by the parents).…”

“…Patients with intermediate interstitial deletion of chromosome 7q have characteristic prenatal and postnatal phenotypes including abnormal skull shape, microcephaly, flat nasal bridge, cleft palate, teeth anomalies, ear malformations, facial dysmorphism, micrognathia, cardiac anomalies, genital anomalies, ectrodactyly, fetal growth restriction, glaucoma, hearing loss, feeding problems, mental retardation and developmental delay [6][7][8][9][10][11][12][13] . Amongst these, fetal growth restriction and developmental delay/mental retardation are the most common, while ectrodactyly is reported in half the cases [6] . Except for the presence of ectrodactyly, our case displayed the characteristic phenotypical features: fetal growth restriction, wide nasal bridge, low-set ears and cleft palate while prominent cheeks and nuchal skin had never been reported.…”

“…In addition to aneuploidies, other chromosomal abnormalities such as translocations, deletions and derivations have also been detected through this prenatal screening [5] . From the review of the literature, the incidence of interstitial deletion of the long arm of chromosome 7 at band 21 is exceedingly rare [6] . Herein, we report the first described case of a prenatally detected intermediate interstitial deletion of chromosome 7q with the aid of the combined first-trimester DS screening.…”