Lighthouse; Migraine; Fool's Gold

Three original poems

Genetic screening protocol for familial hypercholesterolemia which includes splicing defects gives an improved mutation detection rate

Familial hypercholesterolemia (FH) is a common single gene disorder, which predisposes to coronary artery disease. In a previous study, we have shown that in patients with definite FH around 20% had no identifiable gene defect after screening the entire exon coding area of the low density lipoprotein receptor (LDLR) and testing for the common Apolipoprotein B (ApoB) R3500Q mutation. In this study, we have extended the screen to additional families and have included the non-coding intron splice regions of the gene. In families with definite FH (tendon xanthoma present, n = 68) the improved genetic screening protocol increased the detection rate of mutations to 87%. This high detection rate greatly enhances the potential value of this test as part of a clinical screening program for FH. In contrast, the use of a limited screen in patients with possible FH (n = 130) resulted in a detection rate of 26%, but this is still of significant benefit in diagnosis of this genetic condition. We have also shown that 14% of LDLR defects are due to splice site mutations and that the most frequent splice mutation in our series (c.1845 + 11 c > g) is expressed at the RNA level. In addition, DNA samples from the patients in whom no LDLR or ApoB gene mutations were found, were sequenced for the NARC-1 gene. No mutations were identified which suggests that the role of NARC-1 in causing FH is minor. In a small proportion of families (

Mutation screening and genotype:phenotype correlation in familial hypercholesterolaemia

The aim of this study was to develop a mutation screening protocol for familial hypercholesterolaemia (FH) patients and to assess genotype/phenotype effects in terms of pre-treatment lipid profiles and presentation of tendon xanthomata (TX). A total of 158 families with clinical definitions of possible (120) or definite (38) FH were studied using a tiered screening protocol. Mutations were identified in 52 families, 44 families showing 23 different LDLR gene defects and eight families showing the common Apo B100 gene defect R3500Q. LDLR defects were detected in various regions of the gene with 56% in the LDL binding domain (exons 2-6) and 37% in the EGF precursor homology domain (exons 7-14). The most common mutations were D461N(7), C210X(5), 932delA(5), and C163Y(4). Frameshift mutations accounted for 20% with nonsense 13%, mis-sense 35%, splice 3%, Apo B 13% and 2% large deletion, 13% of clinically definite FH remained undefined. In conclusion, DNA based diagnosis is possible in 79% (30/38) of clinically definite FH families and of the 120 possible FH families at the start of the screening program, 18% (22/120) now have defined mutations. Overall 60 families from the original 158 meet the clinical and/or genetic criteria for definite FH. Tendon xanthomata were present in only 58% (30/52) of genetically defined FH families, thus limiting its use as a strict diagnostic criteria. Families with low density lipoprotein receptor (LDLR) defects present with higher total and LDL cholesterol levels and a higher incidence of TX than do those with the common Apo B variant, and frameshift mutations appear to have the most severe presentation. Copyright (C) 1999 Elsevier Science Ireland Ltd.

Genotype/phenotype correlations in familial hypercholesterolaemia

It is now possible to identify the specific gene defect in the majority of patients with familial hypercholesterolaemia. A potential benefit of this knowledge, in addition to helping with family screens, is to be able to predict the future clinical course. In order to do this, detailed genotype/phenotype correlation studies are required.

Familial exudative vitreoretinopathy associated with nonneovascular chronic angle-closure glaucoma

Purpose: Cases of angle-closure glaucoma in patients with familial exudative vitreoretinopathy have been reported secondary to neovascularization of the anterior segment. Cases secondary to nonneovascular mechanisms have not been previously reported. Methods: Two cases are presented of angle-closure glaucoma as a result of a nonneovascular mechanism. Results: Neovascularization was found to be a very unlikely explanation for the angle closure in these two cases. Conclusion: There may be an association between familial exudative vitreoretinopathy and angle-closure glaucoma as a direct result of a retrolental process or more likely a relative lens-iris pupillary block with a large lens.

Familial hypocalciuric hypercalcaemia as a differential diagnosis of hyperparathyroidism:studies in a large kindred and a review of surgical experience in the condition

We have studied 46 members of a large kindred with familial hypocalciuric hypercalcaemia (FHH) after a neck exploration failed to cure hypercalcaemia in an asymptomatic patient. Serum calcium, serum phosphate, plasma parathormone and vitamin D metabolites do not distinguish affected members from patients with hyperparathyroidism. Because of the continuing debate as to whether or not FHH is a variant of, or distinct from, hyperparathyroidism, we have carried out a review of surgical experience with subtotal parathyroidectomy in hyperparathyroidism secondary to parathyroid hyperplasia and in FHH. Whereas the procedure is successful in 90 per cent of the former cases only one case of FHH has been cured by it. This provides evidence for the two conditions being aetiologically distinct. Before patients with asymptomatic hypercalcaemia are referred for parathyroid surgery the calcium:creatinine clearance ratio should be measured using a 2 h urine sample collected after an overnight fast and a fasting blood sample. If this ratio is less than 0.01 then screening of first degree relations should be undertaken before any parathyroid surgery is performed. Unnecessary surgery can therefore be avoided.

Transmission of two novel mutations in a pedigree with familial lecithin:cholesterol acyltransferase deficiency:structure-function relationships and studies in a compound heterozygous proband

Two novel mutations were identified in a compound heterozygous male with lecithin:cholesterol acyltransferase (LCAT) deficiency. Exon sequence determination of the LCAT gene of the proband revealed two novel heterozygous mutations in exons one (C110T) and six (C991T) that predict non-conservative amino acid substitutions (Thr13Met and Pro307Ser, respectively). To assess the distinct functional impact of the separate mutant alleles, studies were conducted in the proband's 3-generation pedigree. The compound heterozygous proband had negligible HDL and severely reduced apolipoprotein A-I, LCAT mass, LCAT activity, and cholesterol esterification rate (CER). The proband's mother and two sisters were heterozygous for the Pro307Ser mutation and had low HDL, markedly reduced LCAT activity and CER, and the propensity for significant reductions in LCAT protein mass. The proband's father and two daughters were heterozygous for the Thr13Met mutation and also displayed low HDL, reduced LCAT activity and CER, and more modest decrements in LCAT mass. Mean LCAT specific activity was severely impaired in the compound heterozygous proband and was reduced by 50% in individuals heterozygous for either mutation, compared to wild type family members. It is also shown that the two mutations impair both catalytic activity and expression of the circulating protein.

How to classify the Oldest Old according to Health Status: A study of 1160 subjects belonging to 552 90+ Italian sibships characterised by familial longevity recruited within the GeHA EU project

The health status of the oldest old, the fastest increasing population segment worldwide, progressively becomes more heterogeneous, and this peculiarity represents a major obstacle to their classification. We compared the effectiveness of four previously proposed criteria (Franceschi et al., 2000; Evert et al., 2003; Gondo et al., 2006; Andersen-Ranberg et al., 2001) in 1160 phenotypically fully characterized Italian siblings of 90 years of age and older (90+, mean age: 93 years; age range: 90–106 years) belonging to 552 sib-ships, recruited in Northern, Central and Southern Italy within the EU-funded project GEHA, followed for a six-year-survival. Main findings were: (i) ‘‘healthy’’ subjects varied within a large range, i.e. 5.2% (Gondo), 8.7% (Evert), 17.7% (Franceschi), and 28.5% (Andersen-Ranberg); (ii) Central Italy subjects showed better health than those from Northern and Southern Italy; (iii) mortality risk was correlated with health status independently of geographical areas; and (iv) 90+ males, although fewer in number, were healthier than females, but with no survival advantage. In conclusion, we identified a modified version of Andersen-Ranberg criteria, based on the concomitant assessment of two basic domains (cognitive, SMMSE; physical, ADL), called ‘‘Simple Model of Functional Status’’ (SMFS), as the most effective proxy to distinguish healthy from not-healthy subjects. This model showed that health status was correlated within sib-ships, suggesting a familial/genetic component.

Prevalence of germ-line mutations in p16, p19ARF, and CDK4 in familial melanoma:analysis of a clinic-based population

Five to ten percent of individuals with melanoma have another affected family member, suggesting familial predisposition. Germ-line mutations in the cyclin-dependent kinase (CDK) inhibitor p16 have been reported in a subset of melanoma pedigrees, but their prevalence is unknown in more common cases of familial melanoma that do not involve large families with multiple affected members. We screened for germ-line mutations in p16 and in two other candidate melanoma genes, p19ARF and CDK4, in 33 consecutive patients treated for melanoma; these patients had at least one affected first or second degree relative (28 independent families). Five independent, definitive p16 mutations were detected (18%, 95% confidence interval: 6%, 37%), including one nonsense, one disease-associated missense, and three small deletions. No mutations were detected in CDK4. Disease-associated mutations in p19ARF, whose transcript is derived in part from an alternative codon reading frame of p16, were only detected in patients who also had mutations inactivating p16. We conclude that germ-line p16 mutations are present in a significant fraction of individuals who have melanoma and a positive family history.

Tele-Supervised FES-Assisted Exercise for Hemiplegic Upper Limb

Stroke survivors often have upper limb (UL) hemiparesis, limiting their ability to perform activities of daily life (ADLs). Intensive, task-oriented exercise therapy (ET) can improve UL function, but motivation to perform sufficient ET is difficult to maintain. Here we report on a trial in which a workstation was deployed in the homes of chronic stroke survivors to enable tele-coaching of ET in the guise of computer games. Participants performed 6 weeks of 1 hour/day, 5 days/week ET. Hand opening and grasp were assisted with functional electrical stimulation (FES). The primary outcome measure was the Action Research Arm Test (ARAT). Secondary outcome measures included a quantitative test of UL function performed on the workstation, grasp force measurements and transcranial magnetic stimulation (TMS). Improvements were seen in the functional tests, but surprisingly, not in the TMS responses. An important finding was that participants commencing with intermediate functional scores improved the most.

CONCLUSIONS: 1) Daily, tele-supervised FES-ET in chronic stroke survivors is feasible with commercially-available technology. 2) The intervention can significantly improve UL function, particularly in people who start with an intermediate level of function. 3) Significant improvements in UL function can occur in the absence of changes in TMS responses.

Adaptor protein-2 sigma subunit mutations causing familial hypocalciuric hypercalcaemia type 3 (FHH3) demonstrate genotype-phenotype correlations, codon bias and dominant-negative effects

The adaptor protein-2 sigma subunit (AP2sigma;2) is pivotal for clathrin-mediated endocytosis of plasma membrane constituents such as the calcium-sensing receptor (CaSR). Mutations of the AP2sigma;2 Arg15 residue result in familial hypocalciuric hypercalcaemia type 3 (FHH3), a disorder of extracellular calcium (Ca<inf>o</inf>²⁺) homeostasis. To elucidate the role of AP2sigma;2 in Ca<inf>o</inf>²⁺ regulation, we investigated 65 FHH probands, without other FHH-associated mutations, for AP2sigma;2 mutations, characterized their functional consequences and investigated the genetic mechanisms leading to FHH3. AP2sigma;2 mutations were identified in 17 probands, comprising 5 Arg15Cys, 4 Arg15His and 8 Arg15Leu mutations. A genotype-phenotype correlation was observed with the Arg15Leu mutation leading to marked hypercalcaemia. FHH3 probands harboured additional phenotypes such as cognitive dysfunction. All three FHH3-causing AP2sigma;2 mutations impaired CaSR signal transduction in a dominant-negative manner. Mutational bias was observed at the AP2sigma;2 Arg15 residue as other predicted missense substitutions (Arg15Gly, Arg15Pro and Arg15Ser), which also caused CaSR loss-of-function, were not detected in FHH probands, and these mutations were found to reduce the numbers of CaSR-expressing cells. FHH3 probands had significantly greater serum calcium (sCa) and magnesium (sMg) concentrations with reduced urinary calcium to creatinine clearance ratios (CCCR) in comparison with FHH1 probands with CaSR mutations, and a calculated index of sCa × sMg/100 × CCCR, which was ≥ 5.0, had a diagnostic sensitivity and specificity of 83 and 86%, respectively, for FHH3. Thus, our studies demonstrate AP2sigma;2 mutations to result in a more severe FHH phenotype with genotype-phenotype correlations, and a dominant-negative mechanism of action with mutational bias at the Arg15 residue.