Journal of medical genetics
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Pulmonary lymphangioleiomyomatosis (LAM) is a rare disorder limited almost exclusively to women of reproductive age. LAM affects about 5% of women with tuberous sclerosis complex (TSC). LAM also occurs in women who do not have TSC (sporadic LAM). ⋯ No TSC2 mutations were detected. We did find three silent TSC2 polymorphisms. We conclude that patients with sporadic LAM, including those with renal angiomyolipomas, do not have a high frequency of germline mutations in the coding region of TSC2.
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We report a 9 year old girl with microcephaly and self-limiting dilated cardiomyopathy. Additional features include mental retardation, delayed developmental milestones, and minor dysmorphic features. This is the second reported case of this phenotype, which is believed to be a new autosomal recessive syndrome.
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Point mutations in the ryanodine receptor (RYR1) gene are associated with malignant hyperthermia, an autosomal dominant disorder triggered in susceptible people (MHS) by volatile anaesthetics and depolarising skeletal muscle relaxants. To date, 17 missense point mutations have been identified in the human RYR1 gene by screening of the cDNA obtained from muscle biopsies. Here we report single strand conformation polymorphism (SSCP) screening for nine of the most frequent RYR1 mutations using genomic DNA isolated from MHS patients. ⋯ We analysed 57 unrelated patients and detected seven of the known RYR1 point mutations. Furthermore, we found a new mutation, Arg2454His, segregating with the MHS phenotype in a large pedigree and a novel amino acid substitution at position 2436 in another patient, indicating a 15.8% frequency of these mutations in Italian patients. A new polymorphic site in intron 16 that causes the substitution of a G at position -7 with a C residue was identified.
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Case Reports
Anomalous right pulmonary artery origins in association with the fetal valproate syndrome.
Two cases are reported of fetal valproate syndrome in association with anomalous right pulmonary artery origin. Both diagnoses were confirmed following cardiac catheterisation as echocardiography alone was inadequate to define the anatomy. Anomalous right pulmonary artery origin is extremely rare making a chance association with fetal valproate syndrome very unlikely. We recommend that anomalous pulmonary artery origin is borne in mind in patients with valproate syndrome undergoing cardiac assessment, particularly as this may be a difficult diagnosis to make on echocardiography.
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Cowden syndrome (CS) or multiple hamartoma syndrome (MIM 158350) is an autosomal dominant disorder with an increased risk for breast and thyroid carcinoma. The diagnosis of CS, as operationally defined by the International Cowden Consortium, is made when a patient, or family, has a combination of pathognomonic major and/or minor criteria. The CS gene has recently been identified as PTEN, which maps at 10q23.3 and encodes a dual specificity phosphatase. ⋯ This mutation occurred at the last nucleotide of exon 3 and within a region homologous to the cytoskeletal proteins tensin and auxilin. We conclude that germline PTEN mutations play a relatively minor role in CS-like families. In addition, our data would suggest that, for the most part, the strict International Cowden Consortium operational diagnostic criteria for CS are quite robust and should remain in place.