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Microdeletions of 1q41q42 have recently been classified as a syndrome. Features include significant developmental delay and characteristic dysmorphic features as well as cleft palate, clubfeet, seizures, and short stature in some individuals, with a clinical diagnosis of Fryns syndrome in two individuals with congenital diaphragmatic hernia at the severe end of the spectrum. The gene DISP1, which is involved in sonic hedgehog signaling, has been proposed as a candidate for the midline defects in this syndrome. We undertook a genotype-phenotype analysis of seven previously unreported individuals with deletions of 1q41q42 that range from 777 kb to 6.87 Mb. Three of the individuals in our cohort do not display the major features of the syndrome and have more proximal deletions that only overlap with the previously described 1q41q42 smallest region of overlap (SRO) at DISP1. One individual with several features of the syndrome has a more distal deletion that excludes DISP1. The three remaining individuals have larger deletions that include the entire SRO and demonstrate features of the microdeletion syndrome. Confounding genotype-phenotype correlations, one of the small deletions involving DISP1 was inherited from a phenotypically normal parent. DISP1 haploinsufficiency may not be solely responsible for the major features of 1q41q42 microdeletion syndrome, and other genes in the SRO likely play a role in the phenotype. Additionally, some features present in a minority of individuals, such as Pelger-Huët anomaly, may be attributed to deletions of genes outside of the SRO., (Copyright © 2010 Elsevier Masson SAS. All rights reserved.)

Tracheal agenesis is a rare malformation of the lower respiratory tract. Investigation of a patient with multiple congenital anomalies and tracheal agenesis prompted a review of the literature which uncovered 42 previously published cases, most of whom had other defects. The presence in our patient of a tracheal abnormality in association with radial hypoplasia, single umbilical artery, tetralogy of Fallot, and left hydroureter initially suggested presence of the VACTERL association. However, numerical classification of malformation patterns in the reported patients with tracheal agenesis and in a series of patients with tracheoesophageal fistula and other components of the VACTERL association suggests that tracheal agenesis does not occur in the VACTERL association and may be part of another pattern of malformations which includes laryngeal atresia, complex congenital heart anomalies, radial ray defects, and duodenal atresia.