Lack of evidence for connexin 43 gene mutations in human autosomal recessive lateralization defects.

Heterotaxy is the failure of the developing embryo to establish normal left-right asymmetry, which is often associated with multiple malformations. Previous studies have identified different mutations in the cytoplasmic tail of the connexin 43 (cx 43) gene in six patients from a series of six sporadic cases with defects of laterality and severe heart malformations. These cases showed that of the genes involved in lateralization defects with autosomal recessive transmission, cx 43 was the most important. This result was challenged by two different teams, which, on sequencing only the carboxyl terminal end of the cx 43 gene in 30 patients, found no mutations. To assess the responsibility of the cx 43 gene in human autosomal recessive lateralization defects, we tested its involvement in a selected group of 25 patients (19 familial cases) with a wide variety of lateralization defects and cardiovascular malformations. The whole coding sequence and direct flanking sequences were screened for mutations, both by single strand conformation analysis and direct fluorescent sequencing. We could only detect a single base pair insertion in the 3' untranslated region of one patient. To test the possibility of mutations in other parts of the cx 43 gene, the gene was located onto the physical map of chromosome 6, and flanking polymorphic markers were genotyped. Haplotype analysis excluded the cx 43 gene locus in nearly all of the familial cases of lateralization defects. Thus, our results do not support the suggestion that this gene is implicated in human autosomal recessive lateralization defects.

Transcatheter embolization of a residual congenital coronary arteriovenous fistula with a detachable balloon; superiority of interventional cardiology?

A ten-year-old girl who presented with a continuous murmur was diagnosed with a right coronary to right ventricular fistula with colored Doppler echocardiography and selective arteriography. She underwent traditional treatment-ligation of the fistula by sternotomy. Afterwards, the systolic component of the murmur persisted and repeat arteriography showed a residual shunt through the fistula, with no change in the diameter of the right coronary artery. We describe the first case in which a residual fistula was treated with a detachable balloon embolization.

Transcatheter closure of the ductus arteriosus in children and young adults.

Transcatheter occlusion of persistent patent ductus arteriosus (PDA) was attempted in 32 patients (22 female and 10 male, mean age 5.12 +/- 3.98 years, range 9 months to 19.2 years) using Rashkind's occluder device (USCI). Implantation of a second occluder device was attempted in three of the patients. Device embolization to a pulmonary artery occurred in three patients, all with the 12 mm occluder device; two of these devices were retrieved by grabber catheter and the last with thoracotomy without adverse sequelae. Embolization to the right atrium occurred in another patient during a second device implantation attempt because of fluoroscopy problems; this patient required open-heart surgery with sequala of 2 (+) tricuspid insufficiency. In another patient with a significant shunt after the implantation of a 17 mm occluder device, mechanical hemolysis developed, but surgical intervention was not required. The overall complication rate was five out of 35 implantation procedures (14.3%). Besides these, sublingual nifedipine was required for two patients whose systolic blood pressure exceeded 160 mmHg just after the implantation procedure. Sixteen 12 mm and fifteen 17 mm occluder devices were successfully and uneventfully implanted in the first procedure, except for two patients in whom a 17 mm occluder device was implanted after retrieval of an embolized 12 mm occluder. Overall early and mid-term complete occlusion was achieved in 24 patients (75%). Complete occlusion of PDA in the first days after the procedure was achieved in all patients, with the narrowest ductal diameter of less-than 3 mm with the 12 mm occluder device, and less than 6 mm with the 17 mm occluder device.(ABSTRACT TRUNCATED AT 250 WORDS)

Giant congenital coronary artery fistula to left superior vena cava and right atrium with compression of left pulmonary vein simulating cor triatriatum--diagnostic value of magnetic resonance imaging.

A 3-year-old girl with a continuous murmur on auscultation was found to have left coronary artery to right atrial fistula simulating cor triatriatum sinister on echocardiography. Coronary angiography of the patient was also insufficient to clarify the exact pathologic anatomy. Magnetic resonance imaging showed that the main drainage of the aneurysmal coronary artery was to the left superior vena cava, resulting in a diffuse arteriovenous fistula in the lower lobe of the left lung by compressing its pulmonary vein.