Absence of GJA1 gene mutations in four patients with anomalous left coronary artery from the pulmonary artery (ALCAPA).

PROBLEM: Anomalous left coronary artery from the pulmonary artery (ALCAPA) is a rare form of congenital heart disease with no known genetic cause. It is usually diagnosed within the first year of life; it results in myocardial cell death, congestive heart failure and lethality if left untreated. Connexin 43alpha1 is a member of the gap junction family of proteins demonstrated by animal studies to have a role in coronary artery patterning during development. No previous studies have investigated the role of this gene in patients with ALCAPA. METHODS: We forth herein describe the clinical presentation of four patients who presented to the Children's Heart Center at AUBMC and had the final diagnosis of ALCAPA. Screening the GJA1 gene coding for connexin 43alpha1 was undertaken. RESULTS: No mutations were found in the patients or their parents, except for one polymorphism in one of the parents in the 3' untranslated region. All four patients underwent surgical repair with excellent outcome. CONCLUSION: This paper raises the awareness of this rare condition enabling physicians to reach the adequate diagnosis which will allow early surgical intervention and better prognosis. Our patient sample did not exhibit any evidence of association between connexin 43alpha1 and the clinical phenotype.

Pasteurella multocida meningitis in newborns after incidental animal exposure.

We present briefly 2 newborns with Pasteurella multocida meningitis following incidental household exposure to domestic pets and review 36 additional cases from the literature. Of 38 reported cases of P. multocida meningitis during infancy, 18 were less than or equal to 1 month of age. All but one of the infants less than 1 month of age had documented exposure to household dogs and/or cats, most only incidentally.

Differential duplication of an intronic region in the NFATC1 gene in patients with congenital heart disease.

Most forms of congenital heart disease (CHD) result from aberrations in cardiac morphogenesis including errors in septation, valve formation, and proper patterning of the great vessels. Transcription factors are key proteins that dictate mRNA synthesis rate and subsequent protein production in most eukaryotes. NFATC1 belongs to the Rel family of transcription factors. In mice, it is expressed in the embryonic heart and is restricted to the endocardium where it plays a major role in valve formation. To establish a role for NFATC1 in CHD, we started screening for mutations in the exons encoding the DNA-binding domain of NFATC1 in patients enrolled in our study on CHD in Lebanon. DNA was extracted from patients with pulmonary stenosis (PS), tricuspid atresia (TA) and ventricular septal defect (VSD). PCR amplification and DNA sequencing were done on the patients and their parents and (or) siblings. PCR amplification of the exon 7 region showed that 2 bands are obtained in 57% of patients with CHD (32/56) and in 45% of their healthy parents and (or) siblings. Sequencing of the 2 bands revealed that both are amplicons of the exon 7 region, and that the additional band harbors an additional 44 nucleotides segment in the intronic region. The homozygous form of this allele was only present in patients with VSD (2/21). A screen of a pool of 81 healthy, unrelated individuals showed no presence for the homozygous form of this allele, suggesting that NFATC1 is a potential VSD-susceptibility gene.

Regulation of the sphingolipid signaling pathways in the growing and hypoxic rat heart.

Sphingolipids (SLs) have a biomodulatory role in physiological as well as pathological cardiovascular conditions. This study aims to assess the variation of SL mediators and metabolizing enzymes in the growing and hypoxic rat heart. Sprague-Dawley rats were placed in a hypoxic environment at birth. Control animals remained in room air. In control animals, activities of acidic-sphingomyelinase (A-SMase), sphingomyelin synthase (SMS), glucosylceramide synthase (GCS), and ceramidase decreased with age in both ventricles whereas activity of neutral-sphingomyelinase (N-SMase) increased with age. Hypoxic RV mass was 171 and 229% that of controls, at 4 and 8 weeks, respectively. This was accompanied by an increase in RV myocardial ceramide synthesis, consumption and breakdown, with a net effect of suppression of ceramide accumulation and increase in diacylglycerol (DAG) concentration. In addition, significant increase in activities of: A-SMase by 26 and 29%, SMS by 108 and 40%, and ceramidase by 66 and 35%, in the hypoxic RV rats as compared to controls, was noted at 4 and 8 weeks of age, respectively. Sphingolipids and their regulating enzymes appear to play a role in adaptive responses to chronic hypoxia in the neonatal rat heart.

Bilateral percutaneous stent implantation in the pulmonary vasculature: a modality now available in Lebanon.

We report a child with Truncus Arteriosus who developed bilateral proximal branch pulmonary stenosis, following total surgical repair of her condition with construction of the right ventricular outflow tract utilizing a Contegra conduit (Medtronic Inc., Minneapolis, Minn.). The obstruction was relieved completely utilizing bilateral percutaneous stent implantation. To the best of our knowledge, this is the first reported case of bilateral stent implantation to relieve branch pulmonary artery stenosis in Lebanon. This technique could be applied to similar cases of obstruction in the pulmonary tree.