Identification of mutations and evaluation of cardiomyopathy in Turkish patients with primary carnitine deficiency

Primary systemic carnitine deficiency (SCD) is an autosomal recessive disorder caused by defective cellular carnitine transport. Patients usually present with predominant metabolic or cardiac manifestations. SCD is caused by mutations in the organic cation/carnitine transporter OCTN2 (SLC22A5) gene. Mutation analysis of SLC22A5 gene was carried out in eight Turkish patients from six families. Six patients presented with signs and symptoms of heart failure, cardiomyopathy, and low plasma carnitine levels, five of them with concurrent anemia. A patient with dilated cardiomyopathy had also facial dysmorphia, microcephaly, and developmental delay. Tandem MS analyses in siblings of the patients revealed two more cases with low plasma carnitine levels. SCD diagnosis was confirmed in these two cases by mutation screening. These two cases were asymptomatic but echocardiography revealed left ventricular dilatation in one of them. Carnitine treatment was started before the systemic signs and symptoms developed in these patients. Mean value of serum carnitine levels of the patients was 2.63±1.92μmol/L at the time of diagnosis. After 1year of treatment, carnitine values increased to 16.62±5.11 (p<0.001) and all responded to carnitine supplementation clinically. Mutation screening of the OCTN2 gene study in the patients revealed two novel (p.G411V, p.G152R), and four previously identified mutations (p.R254X, p.R282X, p.R289X, p.T337Pfs12X). Early recognition and carnitine supplementation can be lifesaving in this inborn error of fatty acid oxidation.

Dilated cardiomyopathy in celiac disease: role of carnitine deficiency

Celiac disease (CD) is an immune-mediated enteropathy in genetically susceptible persons and the disease can present with manifestations in the intestine and in organs outside the gut. An increased prevalence of CD in patients with idiopathic dilated cardiomyopathy or secondary cardiomyopathy and some other cardiac disorders has been reported. Here is described a case of dilated cardiomyopathy in a patient with CD and secondary carnitine deficiency. Dilated cardiomyopathy due to carnitine deficiency may occur in CD patients and carnitine deficiency may present not only at the time of diagnosis of CD but it may also develop during gluten-free diet, particularly in patients with fast weight gain and without carnitine supplementation.

Preliminary pediatric transesophageal echocardiography experiences

With transesophageal echocardiography (TEE), a new echocardiographic window is obtained which enables cardiologists to explore the heart from the esophagus and stomach. However, the procedure, when first undertaken, may present certain difficulties for the cardiologist in interpreting the anatomical findings and approaching a diagnosis. We thus convey our first experiences and results of TEE in 107 pediatric patients. Transesophageal echocardiography (TEE) was performed in 107 pediatric patients at our institution between December 1998-February 2001, using the standard techniques and following the standard criteria suggested by the American heart Association. The mean age of 54 male (50.5%) and 53 female (49.5%) patients was 7.8 years. Intubation difficulty was experienced in four cases. In one case, while drawing the transducer back from the esophagus, it kinked at the hypopharynx. None of the cases had major hemorrhage or esophageal rupture, and only a few cases had minor pharyngeal injuries or hemorrhages. We used TEE in detecting vegetations in patients with possible endocarditis, and evaluating the prosthetic valves and abnormal pulmonary venous return. We also used TEE to clarify preooperative anatomical details, postoperative complications and residual defects of complex congenital cardiac anomalies. Transcattheter closure of 47 secundum atrial septal defects (ASD)'s and a muscular ventricular septal defect (VSD) (both during patient selection and during the procedure) were accomplished under TEE guidance. As the pediatric cardiologists gain more experience in performing TEE, this technique will have a wider and more effective use in the pediatric population.

Transcatheter closure of secundum atrial septal defects, a ventricular septal defect, and a patent arterial duct

We report our clinical experience with the newly developed Amplatzer device in transcatheter closure of nine atrial septal defects (ASDs), one ventricular septal defect (VSD), and one patent arterial duct (PDA). Eleven patients with ASD (age range 2.5-18 years) selected according to the location and size of the defect by transesophageal echocardiography (TEE), a five-year-old patient with muscular VSD and a one-year-old patient with PDA were considered for transcatheter closure with Amplatzer devices. All procedures were performed under general anesthesia with fluoroscopic and TEE guidance, following a routine hemodynamic evaluation in the catheter laboratory. The optimal device size was selected after the balloon sizing of the ASDs. The sizes of the VSD and PDA were measured on TEE and angiography. The patients were discharged at 24 hours, after an evaluation with x-ray, electrocardiogram (ECG), and echocardiography; they were on 3-5 mg/kg/day aspirin and infective endocarditis prophylaxis for six months after the procedure. They were reassessed at six to eight weeks and Holter monitoring was done in addition. Devices were used for nine ASD patients, and for the VSD and the PDA patients. Mean ASD size was 14.3 +/- 5.3 mm at TEE and 18.3 +/- 4.3 mm at balloon sizing (p=0.02). The mean size of the device was 18.7 +/- 4.2 mm. The procedure time and the fluoroscopy time were 46.1 +/- 12.3 and 12.9 +/- 1.6 minutes, respectively. Immediately after the procedure, four patients (44%) had trivial shunts (TS). TS remained in only two during discharge, and no shunt was observed at second evaluation. The devices were similarly applied to VSD (12-7 mm) and PDA (8-6 mm) patients. Both cases had TS immediately, which disappeared at 24 hours. None of the patients had major complications. Junctional rhythm developed in one patient, and another patient had frequent supraventricular extrasystoles. Amplatzer is an effective and safe device for transcatheter closure of ASD, VSD, or PDA, especially in pediatric patients.

Endovascular stent implantation in congenital heart defects

We report the immediate and short-term results of endovascular stent implantations from our center. We performed stent implantations in four patients (3, 12, 18 and 20 years old) with different stenoses or obstructions: right ventricular outflow conduit obstruction, left Blalock-Taussig obstruction, post-operative recoarctation and cavopulmonary anastomosis obstruction. Stent were implanted successfully. The mean diameters of stenoses were expanded from 4.5 +/- 3.5 (2-7) mm to 9 +/- 1. 2 (8-10) mm, and the complaints of patients were improved significantly by stent implantation. There was no complication related to the procedures. All patients are living except one who died from cerebrovascular event unrelated to the stent implantation. The mean follow-up period of three living patients is 6.3 +/- 5.5 (1-2) months. As of the last control, all have remained at the caliber achieved at original placement. In light of our limited experience and previous reported studies, we conclude that intravascular stents are safe and can be used effectively in selected patients with congenital heart defects.

Congenital sick sinus syndrome with breath holding and severe syncope episodes during infancy. A case report

Sick sinus syndrome is a rare cause of bradycardia in children without structural heart disease. A case of profound sinus bradycardia, sinus arrest with junctional escape, and pauses in a two-year-old infant with breath-holding and syncope episodes is presented. As a result of these clinical symptoms and electrocardiographic findings, the patient with sick sinus syndrome underwent implantation of transvenous ventricular pacemaker. He has been well and asymptomatic since the insertion of the pacemaker. In the differential diagnosis of an infant with breath-holding and syncope episodes, when these symptoms in particular cannot be explained by other common reasons, sick sinus syndrome should be kept in mind. This case also illustrates the importance of electrocardiographic studies for the diagnosis.

Dilatation of a restrictive interatrial communication using a balloon angioplasty catheter

Balloon atrioseptostomy is a life-saving procedure palliating certain congenital heart defects like transposition of the great arteries, right or left atrioventricular valve atresia, hypoplastic left heart syndrome, and pulmonary hypertension. Occasionally the Rashkind balloon septostomy technique may be ineffective in creating an adequate interatrial communication. We performed balloon dilatation of a restricted atrial septal defect using a balloon angioplasty catheter in a three-month-old infant.

Guanosine triphosphate cyclohydrolase I deficiency: a rare cause of hyperphenylalaninemia

Tetrahydrobiopterin (BH4) deficiencies are a heterogeneous group of disorders caused by a defect in two of the three enzymes involved in its biosynthesis or in the two recycling enzymes. Except for the deficiency of dehydratase, an enzyme catalyzing a reaction in the recycling pathway, all other variants of BH4 deficiency are characterized by developmental delay, progressive neurological deterioration, hypokinesis, drooling, swallowing difficulty, truncal hypotonia, increased limb tone, myoclonus and brisk deep tendon reflexes. A deficiency of guanosine triphosphate cyclohydrolase I (GTPCH), the first enzyme in the biosynthetic pathway of BH4, is described in a 14-month-old male infant with hyperphenylalaninemia, developmental delay, hypertonia of the extremities, seizures, feeding difficulties, and vomiting. Urinary pteridine screening revealed very low levels of neopterin and biopterin which was highly suggestive of GTPCH deficiency. Low cerebrospinal fluid concentrations of 5-hydroxyindoleacetic acid (5HIAA) and homovanillic acid concentrations, together with no detectable neopterin and decreased concentrations of biopterin and folate, agreed with the diagnosis of GTPCH deficiency. Subsequently measured neopterin and biopterin synthesis in cytokine-stimulated skin fibroblasts confirmed GTPCH deficiency, albeit indirectly. The patient showed marked improvement on a low-protein low-phenylalanine diet with neurotransmitter precursor administration. The favorable outcome in this patient clearly shows that not only newborns with elevated phenylalanine levels but also older children with neurological signs and symptoms should be screened for a BH4 deficiency in order to have maximum benefit of the treatment.

High initial and acquired drug resistance in pulmonary tuberculosis in Turkey

SETTING

Süreyyapasa Center for Chest Diseases and Thoracic Surgery, Istanbul, Turkey between January 1992 and December 1992.

OBJECTIVE

To evaluate the prevalances of initial and acquired resistance to antituberculosis drugs in our center.

DESIGN

785 patients with pulmonary tuberculosis (both old = 525/785 and new = 260/785 cases) referred to our center were evaluated with respect to their drug resistance patterns.

RESULTS

The overall resistance rate (1 or more drugs) was 35.5%, with initial resistance 26.6% (140 of 525) and acquired resistance 53.4% (139 of 260). Initial resistance to streptomycin was the most frequent (20.6%), followed by rifampicin (10.8%), isoniazid (5.1%) and ethambutol; (4.2%). Initial resistance was noted as 16.4% to 1 drug, 7.7% to 2 drugs, 1.2% to 3 drugs and 1.3% to 4 drugs. Acquired resistance to rifampicin was the most frequent (36.2%) followed by streptomycin 31.9%, and isoniazid 30%. Acquired resistance was found as 18.7% to 1 drug, 19.3% to 2 drugs, 9.6% to 3 drugs and 5.8% to 4 drugs.

CONCLUSION

High initial drug resistance in Turkey may well threaten the success rates of antituberculosis treatment and it is therefore mandatory to begin antituberculosis treatment in routine practice in our country with at least 4 first-line drugs, replacing streptomycin with ethambutol due to high resistance to streptomycin. In conclusion there is an urgent need for a nationwide tuberculosis control programme in Turkey, where the treatment of old cases is still challenging, in order to combat the grave situation of high initial and acquired drug resistance.