1106 Twins with uncertain significant mutations, slightly different cardiomyopathies and different oucmes

Dilated cardiomyopathy (DCM) is defined as left ventricle (LV) dilatation and dysfunction in the absence of abnormal loading conditions or coronary artery disease enough to cause global systolic impairment. It is the leading cause of heart failure and sudden cardiac death, and even in the early stages of life 5,7/1.000.000 children are diagnosed each year. Lately, genetic screening has revealed that 30-50% of the cases have a familial origin, with a high genetic heterogeneity.

We present the case of a 4-month-old boy (case A) referred to our Hospital with high suspicion of dilated cardiomyopathy. He had a twin brother, pregnancy went without complications, pre-birth ultrasound and blood tests were completely normal and a caesarean birth was planned at 37 weeks of pregnancy. He also has an older sibling with no medical history. Our patient was the first to be born and was admitted to the neonatal-ICU due to tachypnea, labored breathing and desaturation. In the physical exam a 5cm hepatomegaly was detected and on the X-Ray a cardiomegaly and enlarged mediastinum were confirmed. ECG showed no electrical abnormalities besides vague repolarization changes. A TTE was done, showing remarkable left cavities enlargement with severe left ventricle dysfunction and moderate mitral regurgitation, comprising the right filling and therefore the right cardiac output. These findings were confirmed by MRI, not detecting enhancement patterns compatible with myocarditis. A genetic test was performed in the index case detecting the presence of a mutation in the desmin gene (Des C.568 + 10c) and the myosin heavy chain 7 gene (Myh7p - glu883Ala) both associated either with dilated and noncompaction cardyomiopathies. Due to the elevated chances of a familiar-DCM his twin brother was admitted to study (case B), with no symptoms or clinical signs besides an isolated bronchitis episode. The clinical examination and EKG were normal, detecting in the TTE a slightly dilated left ventricle with non-compactation morphology in the LV lateral wall, but no left ventricle dysfunction. Also, a TTE was performed in their father with similar findings: mild LV dilatation with minor systolic disfunction and uncertain non-compactation morphology in the LVl apex.

Abnormalities of specific genes are now known to be responsible for different types of congenital heart diseases with important implications in genetic counseling. We want to emphasize the different manifestation of a single mutation on different members of a family, even in this two twin-brothers that, under the same probable conditions during preganancy, had slightly different cardyomyopathies but very different severity, and probable mid to long term prognosis.

Abstract 1106 Figure.

P1337 Left ventricle outpouchings. Assesing diagnostic complexity

Congenital left ventricle outpouchings (LVO) are a very rare condition that include left ventricle accessory chamber, left ventricle aneurysm (LVA), left ventricle diverticulum (LVD), double-chambered left ventricle and accessory left ventricle, without well-stablished diagnostic criteria. A recent article by Elaheh Malakan et al tries to show this difficulties and propose an algorithm to help define this different pathologies.

We present the case of a 26-day-old boy that was admitted to our Hospital with suspicion of dilated cardiomyopathy. In his physical exam a systolic murmur was detected, and his mother described tiredness during intakes and tachypnea. His ECG showed a sinus rhythm, with an 80º QRS axis. No signs of hypertrophy or dilated cavities were detected. As part of the study a TTE was performed, detecting a dilated left ventricle with a tract crossing the apical side from the LV lateral wall. The MRI confirmed the presence of an incomplete muscular septum from de LV lateral wall up to the apex encompassing the papillary muscles in the mid left ventricle, dividing the LV in two chambers with telediastolic size of 3.5x3cm and 2.6x2.4cm respectively. This secondary appendix, with a pseudoaneurysm morphology, distended in systole with a dyskinetic motion. Globally, the left ventricle was dilated and had mild systolic disfunction. The right cavities were morphological and functionally normal.

In this case initially a common dilated cardiomyopathy was suspected, being able to confirm the presence of a muscular tract crossing the mid left ventricle. The MRI described the image as an LV pseudoaneurysm, however the TTE images and the diagnostic algorithm proposed by Elaheh Malakan et al would include this case as a two-chamber left ventricle, denoting the still present difficulties in the diagnostic process in these cases, and its impact in their therapeutic approach.

Abstract P1337 Figure.

[Use of stents in pediatric cardiology. Initial results]

BACKGROUND AND AIM

Balloon-expandable stents are useful in treating vascular stenotic lesions associated with congenital heart defects. We report our experience of this device since 1997.

PATIENTS AND METHOD

Seventeen stents were implanted in 12 children in 13 procedures. The mean age of the patients was 82 months (range: 2-168 months). Eight patients had postsurgical stenoses in branch pulmonary arteries, three patients had aortic re-coarctation and one patient had a ductus-dependent complex heart defect. In the first eight patients we performed right catheterization, following the usual technique of percutaneous implantation with super-stiff wire and Mullins sheath. In the remaining patients, vascular access was through the femoral artery. The Palmaz stent was used in 13 patients, Express stents in three and Intrastent in one patient.

RESULTS

After stent implantation, the diameter of the narrowings increased from 3.1 mm (2.8-5.6) to 12 mm (10-15) (p < 0.002) and the gradient was reduced from 32 mmHg (21-45) to 8.5 mmHg (0-11.5) (p < 0.002). In the patient with ductus-dependent heart defect, the procedure allowed prostaglandin E1 withdrawal and hospital discharge. After a mean follow-up of 27 months (range: 1-60 months) one occurrence of late complete occlusion of branch pulmonary artery and one case of side-branch partial occlusion (right superior lobe branch) have been detected. One patient died from causes unrelated to the stent (prior cardiogenic shock). The remaining patients are asymptomatic and medication free.

CONCLUSION

The stent is a safe and effective device that could be used in a wide variety of stenotic vascular lesions.

Congenital erythropoietic porphyria affecting two brothers

We report two brothers, aged 5 and 2 years, with typical features of congenital erythropoietic porphyria. The elder did not receive medical attention until the age of 2 years, even though his urine had been red almost from birth, and despite severe scarring of the hands and face. The younger brother suffered haemolysis at birth. The uroporphyrinogen III cosynthase (URO IIIS) enzyme activity of red blood cells was 2% and 1.2% in the brothers, and genetic studies showed two different mutations of the URO IIIS gene, C73R and P248Q. The latter is a recently described mutation.

A systematic analysis of the mutations of the uroporphyrinogen III synthase gene in congenital erythropoietic porphyria

Congenital erythropoietic porphyria (CEP) or Günther's disease is an inborn error of heme biosynthesis, transmitted as an autosomal recessive trait and characterized by a profound deficiency of uroporphyrinogen III synthase activity (UROIIIS). The molecular defects observed in CEP are mainly heterogeneous, except for one missense mutation, C73R (Cys to Arg substitution at codon 73) which represents nearly 40% of the disease alleles. A convenient strategy was designed to establish a rapid diagnosis at the genetic level in samples from patients with CEP. As a first step, the most frequent mutation is searched for by restriction analysis from genomic. DNA amplified by PCR. Next, the nine coding exons and intron-exon boundaries are sequenced from genomic DNA. As an alternative, the mutation can be determined by sequencing the UROIIIS cDNA of the patient, using the RT-PCR technique on RNAs when a lymphoblastoid cell line can be established. Finally, for each new mutation in UROIIIS coding sequence, the corresponding mutant protein is expressed in Escherichia coli, in order to demonstrate the pathological significance of the mutation. This work describes the analysis of UROIIIS gene mutations in 10 new families with CEP and summarizes the data from 20 unrelated families studied in our laboratory. Three new missense mutations of UROIIIS coding sequence (H173Y, Q187P and P248Q) have been observed together with 8 known mutations. The significance of three intronic base changes (476 -31 T-->C; 562 -4 A-->T; 562 -23 A-->G) is discussed. In 6 alleles out of 40 (15%), the mutation remains undetermined.

[Guillain-Barre syndrome in children. Analysis of 23 cases]

A group of 23 children aged 5 months to 6 years a diagnosis of Guillain Barré syndrome has been analysed. In 2/3 of our patients the illness appeared in autumn-winter period. We considered muscle weaknesses, pain and impairments of cranial nerves to be the main characteristics of the disease. The presence of denervation activity was an indication of worse evolutive prognosis. Hormone treatment was started in 21 cases and plasma exchange in one more, with rapid reduction of the vegetative and the motor symptoms. The progress was considered to be highly favourable in all of them. One child had a recidivant form of this disease.