Analysis of cardiac anomalies in VACTERL association.

BACKGROUND: Congenital heart disease (CHD) is estimated to affect between 3 and 5% of all newborns. Extra-cardiac malformations are observed in 7 to 50% of patients with CHD. One relatively well-known association that can occur in the context of CHD is VACTERL. Controversy still remains regarding the definition of VATER association and its expansion to VACTERL, the appropriate diagnostic criteria and the overall incidence. METHODS: We conducted a description of a case series to characterize the cardiac findings present in a cohort of patients meeting the criteria for VACTERL association. RESULTS: Forty-six of 220 were eligible for inclusion into the study, 67% (31 of 46) had CHD. The most common CHD was ventricular septal defect, present in 18 of 31 patients (58%). There was no statistically significant association between CHD severity and the presence or absence of other VACTERL component features, specifically anorectal malformation (p = 0.18) or tracheo-esophageal fistula (p = 0.72). CHD presence also did not correlate with the presence of tracheo-esophageal fistula or anorectal malformation. CONCLUSION: Although this study does not, by design, provide further evidence toward the questions of whether CHD is a defining feature of VACTERL association, the frequency of CHD in our cohort does lend support to it being an important medical consideration in patients with VACTERL association. Based on our experience, we strongly recommend a screening echocardiogram to evaluate for CHD in individuals with a potential diagnosis of VACTERL association.

Holoprosencephaly in a family segregating novel variants in ZIC2 and GLI2.

Holoprosencephaly (HPE) is the most common malformation of the human forebrain. Typical manifestations in affected patients include a characteristic pattern of structural brain and craniofacial anomalies. HPE may be caused by mutations in over 10 identified genes; the inheritance is traditionally viewed as autosomal dominant with highly variable expressivity and incomplete penetrance. We present the description of a family simultaneously segregating two novel variants in the HPE-associated genes, ZIC2 and GLI2, as well as the results of extensive population-based studies of the variant region in GLI2. This is the first time that multiple HPE-associated variants in these genes have been reported in one family, and raises important questions about how clinicians and researchers should view the inheritance of conditions such as HPE.

Analysis of FOXF1 and the FOX gene cluster in patients with VACTERL association.

VACTERL association, a relatively common condition with an incidence of approximately 1 in 20,000 -35,000 births, is a non-random association of birth defects that includes vertebral defects (V), anal atresia (A), cardiac defects (C), tracheo-esophageal fistula (TE), renal anomalies (R) and limb malformations (L). Although the etiology is unknown in the majority of patients, there is evidence that it is causally heterogeneous. Several studies have shown evidence for inheritance in VACTERL, implying a role for genetic loci. Recently, patients with component features of VACTERL and a lethal developmental pulmonary disorder, alveolar capillary dysplasia with misalignment of pulmonary veins (ACD/MPV), were found to harbor deletions or mutations affecting FOXF1 and the FOX gene cluster on chromosome 16q24. We investigated this gene through direct sequencing and high-density SNP microarray in 12 patients with VACTERL association but without ACD/MPV. Our mutational analysis of FOXF1 showed normal sequences and no genomic imbalances affecting the FOX gene cluster on chromosome 16q24 in the studied patients. Possible explanations for these results include the etiologic and clinical heterogeneity of VACTERL association, the possibility that mutations affecting this gene may occur only in more severely affected individuals, and insufficient study sample size.