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1/758. Compound heterozygosity for one novel and one recurrent mutation in a Thai patient with severe protein s deficiency.

    Homozygous or compound heterozygous protein S (PS) deficiency is a very rare disorder in the anticoagulant system, that can lead to life-threatening thrombotic complications shortly after birth. This report describes the results of the genetic analysis of the PROS 1 genes in a Thai girl patient. She was reported in 1990 as the first case with homozygous PS deficiency and neonatal purpura fulminans. In the present report, we identified the mutations in this patient by direct sequencing of PCR products representing all 15 exons of the PROS 1 gene and their flanking intronic regions. The patient turned out to be compound heterozygous for two null mutations. One allele contained a novel sequence variation, an A-insertion in an A5-tract covering codon 146 and 147, that results in a frameshift and a stop codon (TAA) at position 155. The other allele contained a nonsense mutation in exon 12 by a transition at codon 410 CGA (Arg) to TGA (stop). Cosegregation of PS deficiency with these two genetic defects was observed in her family. ( info)

2/758. Benign idiopathic partial epilepsy and brain lesion.

    A 14-year-old girl had severe head trauma from a dog bite at the age of 9 days. This resulted in extensive brain damage, tetraplegia, mental retardation, and epilepsy. The seizures were of rolandic type, and the EEG showed multifocal sharp waves. The course was benign. The initial diagnosis of a pure symptomatic epilepsy was revised after demonstrating typical benign focal sharp waves in the EEG of the healthy sister. Thus a phenocopy of a benign partial epilepsy by the brain lesion could be excluded with sufficient certainty. This observation allows the conclusion that the genetic disposition underlying the sharp-wave trait characteristic of benign partial epilepsies can be involved also in the pathogenesis of seemingly pure symptomatic epilepsies. EEG studies on siblings of such patients are needed to exclude possible phenocopies. ( info)

3/758. neuroblastoma in two siblings supports the role of 1p36 deletion in tumor development.

    Familial neuroblastoma occurs rarely. We studied a family with three children; one of them has a disseminated (stage 4) and another has a localized (stage 2) neuroblastoma. We observed subtelomeric locus D1Z2 (1p36) deletion in both tumors by using double-color fluorescence in situ hybridization. The MYNC gene was found in single copy in both tumors. loss of heterozygosity (LOH) and restriction fragment length polymorphism analyses were performed by using dna from frozen tumor cells and from microdissected tumor areas excised from paraffin-embedded sections. We detected somatic LOH at locus D1S468 (1p36) in a tumor-cell population with a trisomy 1 of the stage-2 patient. neuroblastoma cells of the stage-4 patient were diploid and showed allelic loss at the following loci: D1S172, D1S80, D1S94, D1S243, D1S468, D1S214, D1S241, and D1S164. Haplotype study showed that the siblings inherited the same paternal 1p36-->pter chromosome region by homologous recombination and that, in the two tumors, arm 1p of different chromosomes of maternal origin was damaged. Our results suggest that the siblings inherited the predisposition to neuroblastoma associated with paternal 1p36 region and that tumors developed as a consequence of somatic loss of the maternal 1p36 allele. ( info)

4/758. factor v Leiden and antibodies against phospholipids and protein S in a young woman with recurrent thromboses and abortion.

    We describe the case of a 39-year-old woman who suffered two iliofemoral venous thromboses, a cerebral ischemic infarct and recurrent fetal loss. Initial studies showed high levels of antiphospholipid antibodies (APAs) and a moderate thrombocytopenia. After her second miscarriage, laboratory diagnosis revealed that the woman was heterozygous for the factor v Leiden mutation and had a functional protein s deficiency as well as anti-protein S and anti-beta 2-glycoprotein i antibodies. The impairment of the protein c pathway at various points could well explain the recurrent thromboses in the patient and supports the role of a disturbed protein c system in the pathophysiology of thrombosis in patients with APAs. ( info)

5/758. A germline mutation of the thyrotropin receptor gene associated with thyrotoxicosis and mitral valve prolapse in a Chinese family.

    Activating mutations of the TSH receptor (TSH-R) have been reported to result in toxic adenomas, multinodular goiters, sporadic neonatal hyperthyroidism, and familial autosomal dominant nonautoimmune hyperthyroidism. To date, all descriptions of such mutations, whether somatic or genomic, have been confined to the Caucasian population. We describe a Chinese family in whom a germline proline to serine substitution in position 639 resulted in familial thyrotoxicosis. This constitutively activating mutation has been previously described in a hyperfunctioning thyroid nodule. The three children in this family developed thyrotoxicosis during childhood; their father was diagnosed as thyrotoxic at the age of 38 yr. Two of the children and the father had mitral valve prolapse (MVP) associated with mitral regurgitation. There was a close temporal relationship between the onset of thyrotoxicosis and the diagnosis of mitral valvular disease in these patients. An increased prevalence of MVP has been reported in Graves' disease and chronic lymphocytic thyroiditis, but the pathophysiological mechanisms linking MVP and autoimmune thyroid disease are still not understood. This is the first report of an association between activating TSH-R mutations and MVP. We postulate that TSH-R activation may increase the clinical expression of MVP in genetically predisposed individuals. ( info)

6/758. Neurofibromatosis-noonan syndrome and acute lymphoblastic leukemia: a report of two cases.

    Two boys with neurofibromatosis-noonan syndrome in whom acute lymphoblastic leukemia (ALL) developed are described. Both patients demonstrated B-lineage leukemias with normal cytogenetics. They were treated with combination chemotherapy and remain in remission off therapy. patients with neurofibromatosis-noonan syndrome may be at increased risk for ALL. ( info)

7/758. Molecular assessment of clonality leads to the identification of a new germ line TP53 mutation associated with malignant cystosarcoma phyllodes and soft tissue sarcoma.

    Cystosarcoma phyllodes (CSP) is a rare breast neoplasm composed of stromal and epithelial elements. It usually runs a benign course but it may metastasize. In a 31-year-old patient with recurring CSP, a mesenchymal tumor in the leg developed. The question arose whether the latter tumor could be a metastasis from the CSP, which would have major treatment consequences. The problem was addressed using molecular methods, i.e., comparison of the pattern of polymorphic repeat markers on chromosome 17p as well as single strand conformation polymorphism analysis and sequencing of exons 5 to 8 of the TP53 gene in both tumor and normal tissue. An identical pattern of loss of heterozygosity in both breast tumors was demonstrated, but a different pattern was shown in the tumor in the leg. This led to the conclusion that the latter tumor had to be a new primary tumor. A mutation in codon 162 of the TP53 gene was found in the tumor tissue as well as in the normal tissue of this patient. This germ line mutation leads to the replacement of isoleucine by asparagine and most likely has functional consequences. In all four examined tumors of this patient, the normal TP53 allele was lost. This is strong evidence that this germ line TP53 mutation causes the genesis of these two rare primary mesenchymal tumors in this young patient. The current study exemplifies the power of molecular diagnostic methods in investigating the specific clinical problem of clonal relation between two separate tumors. The germ line mutation found in codon 162 of the TP53 gene and the association with cystosarcoma phyllodes have not been described previously. ( info)

8/758. A distinct difference in clinical expression of two siblings with Aicardi-Goutieres syndrome.

    Two sibs with an encephalopathy, including intracerebral calcification and a white matter disease, are reported. In the younger sister, the cerebrospinal fluid showed chronic pleocytosis and clinically she strictly fits to the diagnosis of Aicardi-Goutieres syndrome. Both sisters were affected by a spastic tetraplegia, truncal hypotonia and dystonic posturing, but the clinical course and the neuroradiological findings were milder in the older sister and she showed no cerebrospinal fluid pleocytosis. The present cases and recent reports of intrafamilial variability of Aicardi-Goutieres syndrome may raise interesting aspects as to the limits and criteria of this syndrome. ( info)

9/758. Respiratory chain deficiency presenting as recurrent myoglobinuria in childhood.

    myoglobinuria is an abnormal urinary excretion of myoglobin due to an acute destruction of skeletal muscle fibres. Several metabolic diseases are known to account for myoglobinuria including defects of glycolysis and fatty acid oxidation. Here, we report on respiratory chain enzyme deficiency in three unrelated children with recurrent episodes of myoglobinuria and muscle weakness (complex I: one patient, complex IV: two patients). All three patients had generalized hyporeflexia during attacks, a feature which is not commonly reported in other causes of rhabdomyolysis. Studying respiratory chain enzyme activities in cultured skin fibroblasts might help diagnosing this condition, especially when acute rhabdomyolysis precludes skeletal muscle biopsy during and immediately after episodes of myoglobinuria. ( info)

10/758. The hPMS2 exon 5 mutation and malignant glioma. Case report.

    patients with Turcot syndrome (TS) are predisposed to colon tumors and primary brain tumors, typically glioblastomas or medulloblastomas. The authors describe a patient with TS featuring a known germline mutation of exon 5 of the hPMS2 mismatch repair gene who developed two metachronous glioblastomas, both with distinct oligodendroglial features. Molecular genetic analysis revealed allelic loss of chromosome 19q in the patient's second tumor but no allelic loss of chromosome 1p. Prominent microsatellite instability was also found in this tumor, consistent with a germline mismatch repair defect. Because this patient had an unusual underlying condition and his tumor had a unique histological appearance for TS, it was hypothesized that this genetic defect may predispose to malignant gliomas with oligodendroglial features. The authors therefore evaluated whether sporadic glioblastomas and oligodendrogliomas undergo mutations of this region of the hPMS2 gene. However, single-strand conformation polymorphism analysis of hPMS2 exon 5 failed to reveal mutations in 20 sporadic glioblastomas and 16 sporadic oligodendroglial gliomas. Thus, although it is possible that the germline hPMS2 exon 5 mutation may predispose to glioblastomas with an oligodendroglial component, the same genetic defect is not commonly involved in sporadic oligodendrogliomas or glioblastomas. ( info)
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