Digeorge anomaly in an infant with deletion of chromosome 22 and dup(9p) due to adjacent type II disjunction

Abstract

A term white girl presented with low birth weight, minor anomalies, and congenital heart defects. The infant had microcephaly, upslanting palpebral fissures, prominent nasal bridge, short philtrum, thin upper lip vermilion, down-turned corners of the mouth, receding mandible, and short broad neck. The hands showed proximal placement of the thumbs, bilateral clinodactyly of the index finger, and bilateral transverse crease. Both hands were clenched, with the index finger overlapping the third finger and the fifth finger overlapping the fourth. There was also talipes calcaneo-valgus, bilateral dorsiflexion of the metatarsophalangeal joints, flexion of the interphalangeal joints, and hypoplasia of all nails. The patient's karyotype was 46,XX,-22, + der(9)t(9;22)(q21.13;q12.1)mat; the mother had the balanced translocation 46,XX,t(9;22)(9pter----9q21.13::22q12.1----22qter++ +;22pter---- 22q12.1::9q21.3----9qter). The infant died at age 10 days, and the autopsy showed absent thyroid isthmus and rudimentary thymus, with one small ectopic parathyroid attached to it. The lungs were hypoplastic, with abnormal lobation. The cardiac anomalies included truncus arteriosus, truncal valve stenosis, single carotid trunk, subclavian arteries arising from the distal part of the aortic arch, atrial and ventricular septal defects, right ventricular hypertrophy, and a hypoplastic left pulmonary artery. Also, multiple small accessory spleens were present in addition to a normal-sized spleen. This case combines features associated with DiGeorge anomaly and dup(9p). The chromosome abnormality in this patient appears to have arisen in a maternal germ cell due to adjacent type II disjunction.

Cryptic telomeric rearrangements in subjects with mental retardation associated with dysmorphism and congenital malformations

“…At necropsy, an atrial septal defect and accessory spleen were recorded. Since accessory spleen has been reported in association with 9p duplication,9 one could speculate that this child was also unbalanced for the maternal translocation, having the der(13) instead of the der(9) found in the proband. In family 4, a paternal cousin was referred with mental retardation.…”

Prevalence of 22q11 microdeletions in DiGeorge and velocardiofacial syndromes: implications for genetic counselling and prenatal diagnosis.

“…The majority of cytogenetically abnormal DGS patients initially reported had unbalanced translocations with monosomy 22pter-.ql 1 . [2][3][4][5][6][7][8][9][10][11] More recently, using high resolution banding techniques, visible interstitial deletions of 22q1 1.2 (del(22)(ql 1.21ql 1.23)) have been identified in approximately 25% of DGS patients. '2 On the basis of the cytogenetic abnormalities, it was hypothesised that the DiGeorge critical region (DGCR) lies within 22q1 1.…”

A Case of Congenitally Absent Left Internal Carotid Artery: Vascular Malformations in 22q11.2 Deletion Syndrome

“…The ICA may take a medial course even when no pharyngeal pulsations are observed on endoscopic examination (Mitnick et al, 1996). A single carotid trunk originating from the aortic arch was previously reported (El-Fouly et al, 1991).…”

“…Defects in pulmonary vessel arborization have been seen (Perez and Sullivan, 2002). Hypoplasia of a pulmonary artery has been reported (El-Fouly et al, 1991). Jugular vein anomalies, isolation of the common carotid artery, and circle of Willis anomalies have previously been associated with 22q11DS (Robin and Shprintzen, 2005).…”