MYH7 variants cause complex congenital heart disease

MYH7, encoding the myosin heavy chain sarcomeric β-myosin heavy chain, is a common cause of both hypertrophic and dilated cardiomyopathy. Additionally, families with left ventricular noncompaction cardiomyopathy (LVNC) and congenital heart disease (CHD), typically septal defects or Ebstein anomaly, have been identified to have heterozygous pathogenic variants in MHY7. One previous case of single ventricle CHD with heart failure due to a MYH7 variant has been identified. Herein, we present a single center's experience of complex CHD due to MYH7 variants. Three probands with a history of CHD, LVNC, and/or arrhythmias were identified to have MYH7 variants through multigene panel testing or exome sequencing. These three patients collectively had 12 affected family members, four with a history of Ebstein anomaly and seven with a history of LVNC. These findings suggest a wider phenotypic spectrum in MYH7-related CHD than previously understood. Further investigation into the possible role of MYH7 in CHD and mechanism of disease is necessary to fully delineate the phenotypic spectrum of MYH7-related cardiac disease. MYH7 should be considered for families with multiple individuals with complex CHD in the setting of a family history of LVNC or arrhythmias.

Local adaptation and archaic introgression shape global diversity at human structural variant loci

Large genomic insertions and deletions are a potent source of functional variation, but are challenging to resolve with short-read sequencing, limiting knowledge of the role of such structural variants (SVs) in human evolution. Here, we used a graph-based method to genotype long-read-discovered SVs in short-read data from diverse human genomes. We then applied an admixture-aware method to identify 220 SVs exhibiting extreme patterns of frequency differentiation - a signature of local adaptation. The top two variants traced to the immunoglobulin heavy chain locus, tagging a haplotype that swept to near fixation in certain southeast Asian populations, but is rare in other global populations. Further investigation revealed evidence that the haplotype traces to gene flow from Neanderthals, corroborating the role of immune-related genes as prominent targets of adaptive introgression. Our study demonstrates how recent technical advances can help resolve signatures of key evolutionary events that remained obscured within technically challenging regions of the genome.

Sudden cardiac death and diabetes mellitus

Sudden cardiac death (SCD) affects a significant percentage of diabetic patients. SCD in these patients can be due to several factors, such as diastolic dysfunction, heart failure, altered platelet function, inflammation, sympathetic nervous stimulation and other factors. In the present review, we discuss the association between diabetes mellitus and SCD.

Cardiovascular risk assessment of South Asians in a religious setting: a feasibility study

AIMS

South Asians in the UK have high cardiovascular disease (CVD) mortality. Therefore, this population is likely to benefit from screening programmes. To address this issue, an initiative was set up between the Royal Free Hampstead NHS Trust, H.E.A.R.T. UK and two Hindu temples in North London to provide screening for CVD risk factors in the community.

METHODS

A total of 434 individuals of Gujarati Indian origin were screened. Measurements included anthropometry, blood pressure and lipid profiles. Three different scoring systems: Framingham, Joint British Societies' 2 and QRISK2 were used to estimate CVD risk.

RESULTS

At least one modifiable CVD risk factor was present in 92% of the individuals screened; 52% were hypertensive, 40% were obese, 75% had central adiposity and 10% had total cholesterol/high density lipoprotein cholesterol ratio > 6. In addition, 37% of a subset of 104 individuals with a fasting sample fulfilled the diagnostic criteria for metabolic syndrome. Overall, 15% of participants screened had a 10-year CV risk score > 20% using QRISK2. The three risk score calculators showed moderate agreement: QRISK2 and JBS2 (kappa 0.61, 95% CI 0.54-0.67), QRISK2 and Framingham (kappa 0.63, 95% CI 0.57-0.70) and JBS2 and Framingham (kappa 0.70, 95% CI 0.64-0.75).

CONCLUSIONS

A high prevalence of modifiable risk factors for CVD was detected in the population screened.

Two functionally distinctive phosphopantetheinyl transferases from amoeba Dictyostelium discoideum

The life cycle of Dictyostelium discoideum is proposed to be regulated by expression of small metabolites. Genome sequencing studies have revealed a remarkable array of genes homologous to polyketide synthases (PKSs) that are known to synthesize secondary metabolites in bacteria and fungi. A crucial step in functional activation of PKSs involves their post-translational modification catalyzed by phosphopantetheinyl transferases (PPTases). PPTases have been recently characterized from several bacteria; however, their relevance in complex life cycle of protozoa remains largely unexplored. Here we have identified and characterized two phosphopantetheinyl transferases from D. discoideum that exhibit distinct functional specificity. DiAcpS specifically modifies a stand-alone acyl carrier protein (ACP) that possesses a mitochondrial import signal. DiSfp in contrast is specific to Type I multifunctional PKS/fatty acid synthase proteins and cannot modify the stand-alone ACP. The mRNA of two PPTases can be detected during the vegetative as well as starvation-induced developmental pathway and the disruption of either of these genes results in non-viable amoebae. Our studies show that both PPTases play an important role in Dictyostelium biology and provide insight into the importance of PPTases in lower eukaryotes.

Epidermal inclusion cyst of the styloid process: a case report

We report an unusual case of epidermal inclusion cyst of the styloid process which presented to us with decreased hearing and tinnitus. The patient underwent complete excision via a combined postaural cervical approach. The unusual location of the tumor and the absence of a history of trauma or intervention in that area added confusion to the diagnosis, which was finally made on histopathology.

Effect of flanking bases on quadruplex stability and Watson-Crick duplex competition

Guanine-rich DNA sequences have the ability to fold into four-stranded structures called G-quadruplexes, and are considered as promising anticancer targets. Although the G-quadruplex structure is composed of quartets and interspersed loops, in the genome it is also flanked on each side by numerous bases. The effect of loop length and composition on quadruplex conformation and stability has been well investigated in the past, but the effect of flanking bases on quadruplex stability and Watson-Crick duplex competition has not been addressed. We have studied in detail the effect of flanking bases on quadruplex stability and on duplex formation by the G-quadruplex in the presence of complementary strands using the quadruplex-forming sequence located in the promoter region of the c-kit oncogene. The results obtained from CD, thermal difference spectrum and UV melting demonstrated the effect of flanking bases on quadruplex structure and stability. With the increase in flank length, the increase in the more favorable DeltaH(vH) is accompanied by a striking increase in the unfavorable DeltaS(vH), which resulted in a decrease in the overall DeltaG(vH) of quadruplex formation. Furthermore, CD, fluorescence and isothermal titration calorimetry studies demonstrated that the propensity to attain quadruplex structure decreases with increasing flank length.

Predicting coronary heart disease risk using the Framingham and PROCAM equations in dyslipidaemic patients without overt vascular disease

AIM

To compare the Framingham and Prospective Cardiovascular Munster (PROCAM) risk calculations.

METHODS

We calculated the risk in 234 dyslipidaemic patients without overt vascular disease and in different subgroups. For example, the proportion of patients with coronary heart disease (CHD) risk >or= 20%, the effect of including the family history (FaHist) and of adjusting raised triglyceride (TG) levels.

RESULTS

The Framingham risk was significantly (p < 0.0001) higher than the PROCAM risk (with and without including the FaHist) in different subgroups and when the TGs were adjusted to 1.7 mmol/l. The percentage of patients with CHD risk >or= 20% calculated by the Framingham (based on systolic or diastolic blood pressure) and PROCAM equations was 21.4% or 23.1% and 16.2% respectively. In the tertile with the highest PROCAM risk, the Framingham score was significantly greater than the PROCAM risk only when the FaHist was included in the Framingham calculation. When we analysed risk by gender, the Framingham score did not differ but the PROCAM risk was significantly (p < 0.0001) greater in men. When TG values were adjusted to 1.7 mmol/l, the predicted risk using PROCAM changed by 0% to -2% in all subgroups.

CONCLUSIONS

In dyslipidaemic patients without overt vascular disease the Framingham model predicted a higher risk than PROCAM. Thus, the Framingham equation probably leads to substantial overtreatment compared with PROCAM. However, according to the literature, even the PROCAM equation may overestimate risk. This has considerable cost implications. New more accurate risk engines are needed to calculate risk in dyslipidaemic patients without overt vascular disease.

Localising and lateralising value of ictal piloerection

BACKGROUND

Piloerection is a rare clinical symptom described during seizures. Previous reports suggested that the temporal lobe is the ictal onset zone in many of these cases. One case series concluded that there is a predominant left hemispheric representation of ictal cold. The aim of this study is to evaluate the localising and lateralising value of pilomotor seizures.

METHODS

Medical records of patients who underwent video electroencephalogram (EEG) monitoring at the Cleveland Clinic between 1994 and 2001 were reviewed for the presence of ictal piloerection. The clinical history, physical and neurological examination, video EEG data, neuroimaging data, cortical stimulation results, and postoperative follow ups were reviewed and used to define the epileptogenic zone. Additionally, all previously reported cases of ictal piloerection were reviewed.

RESULTS

Fourteen patients with ictal piloerection were identified (0.4%). Twelve out of 14 patients had temporal lobe epilepsy. In seven patients (50%), the ictal onset was located in the left hemisphere. Four out of five patients with unilateral ictal piloerection had ipsilateral temporal lobe epilepsy as compared with the ipsilateral side of pilomotor response. Three patients became seizure free after left temporal lobectomy for at least 12 months of follow up. An ipsilateral left leg pilomotor response with simultaneously recorded after-discharges was elicited in one patient during direct cortical stimulation of the left parahippocampal gyrus.

CONCLUSIONS

Ictal piloerection is a rare ictal manifestation that occurs predominantly in patients with temporal lobe epilepsy. Unilateral piloerection is most frequently associated with ipsilateral focal epilepsy. No hemispheric predominance was found in patients with bilateral ictal piloerection.

[Electric brain stimulation for epilepsy therapy]

Attempts to control epileptic seizures by electrical brain stimulation have been performed for 50 years. Many different stimulation targets and methods have been investigated. Vagal nerve stimulation (VNS) is now approved for the treatment of refractory epilepsies by several governmental authorities in Europe and North America. However, it is mainly used as a palliative method when patients do not respond to medical treatment and epilepsy surgery is not possible. Numerous studies of the effect of deep brain stimulation (DBS) on epileptic seizures have been performed and almost invariably report remarkable success. However, a limited number of controlled studies failed to show a significant effect. Repetitive transcranial magnetic stimulation (rTMS) also was effective in open studies, and controlled studies are now being carried out. In addition, several uncontrolled reports describe successful treatment of refractory status epilepticus with electroconvulsive therapy (ECT). In summary, with the targets and stimulation parameters investigated so far, the effects of electrical brain stimulation on seizure frequency have been moderate at best. In the animal laboratory, we are now testing high-intensity, low-frequency stimulation of white matter tracts directly connected to the epileptogenic zone (e.g., fornix, corpus callosum) as a new methodology to increase the efficacy of DBS ("overdrive method").

Painful auras in focal epilepsy

The authors studied the localizing or lateralizing value of painful epileptic auras in 25 patients with focal epilepsy. Painful auras were seen in 4.1% patients with focal epilepsy arising from temporal, frontal, perirolandic, or parieto-occipital regions. Abdominal pain was present in 5% of all abdominal auras in temporal lobe epilepsy and 50% of all abdominal auras in frontal lobe epilepsy. In perirolandic epilepsy, painful somatosensory auras were lateralized contralateral to the epileptic hemisphere but not consistently in temporal lobe epilepsy.

Time to look beyond just lowering the serum concentration of low density lipoprotein--high density lipoprotein levels are also important

There is convincing epidemiological evidence indicating that the serum levels of high density lipoprotein (HDL) cholesterol are inversely related to the risk of vascular events. Similarly, intervention trials, involving healthy populations and patients with coronary heart disease (CHD), have shown that raising the serum levels of HDL is associated with a significant decrease in the risk of vascular events. It follows that serum HDL levels must be considered when assessing risk and setting therapeutic goals. Some of the currently available national treatment guidelines reflect this view. The present review considers the place of serum HDL measurement in the prevention of vascular events.

Potential fluconazole-induced carbamazepine toxicity

OBJECTIVE

To report a case of carbamazepine toxicity resulting from a drug interaction with fluconazole, and to review the possible mechanisms of this interaction.

DATA SOURCES

Medical record review.

DATA SYNTHESIS

A 33-year-old white man with a history of mental retardation and seizures experienced stupor due to carbamazepine toxicity after fluconazole was initiated. The patient had been taking carbamazepine for several years and maintained stable therapeutic concentrations. He started fluconazole therapy after developing a rash presumably due to candidiasis. After admission to the hospital for carbamazepine toxicity, both fluconazole and carbamazepine were withheld and the patient returned to his normal baseline mental status once the carbamazepine concentration declined to a therapeutic range. Carbamazepine was restarted and the patient experienced no further adverse events. Carbamazepine is metabolized by the cytochrome P450 3A4 isoenzyme. Fluconazole is renally excreted but has been noted to inhibit CYP3A4. Fluconazole has also been noted to increase phenytoin concentrations.

CONCLUSIONS

Fluconazole may cause carbamazepine toxicity presumably by inhibiting the cytochrome P450 3A4 isoenzyme.

Effects of recombinant human growth hormone on renal function in children with renal transplants

OBJECTIVE

To provide accurate measurement of renal function during treatment with recombinant human growth hormone (rhGH).

METHODS

We measured glomerular filtration rate and effective renal plasma flow by clearance of inulin and para-aminohippuric acid before rhGH therapy, after 1 week, and then at 6-month intervals for up to 2 years of treatment in 16 children (mean (SD) age = 13.1 (2.2) years; glomerular filtration rate = 52 (27) ml/min per 1.73 m2). The mean (SD) time from transplantation was 6.5 (3.6) years.

RESULTS

Linear growth velocity during rhGH therapy increased from 4.0 (1.8) to 8.8 (2.6) cm/yr (p < 0.0001). One child was withdrawn after 9 months because of abnormal glucose tolerance, and another child received a second renal transplant after 18 months. Glomerular filtration rate increased to 57 (29) ml/min per 1.73 m2 at 1 week (p = 0.004), remained improved at 6 months (63 (30); p = 0.013), but was not significantly better at 1 year (59 (33)). Effective renal plasma flow on day 1 was 237 (127) ml/min per 1.73 m2 and was unchanged on day 8 (244 (123)), at 6 months (271 (149)), and after 1 year (269 (157)). During the study there was no significant change in filtration fraction, blood pressure, or kidney volume, and excretion of microalbumin and N-acetylglucosaminidase was unaltered. There was one rejection episode per 14.8 patient-months in the year before treatment, 1 per 18.9 patient-months during the first year of treatment, and 1 per 13 patient-months during the second year of rhGH therapy.

CONCLUSION

Treatment with rhGH improves growth in children with renal transplants. Glomerular filtration rate was increased after 1 week and 6 months of rhGH therapy but returned to baseline values thereafter. The data indicate the need for long-term follow-up of children with renal transplants who are receiving rhGH.

Differential effects of recombinant human growth hormone on glomerular filtration rate and renal plasma flow in chronic renal failure

In normal subjects recombinant human growth hormone (rhGH) increases glomerular filtration rate (GFR) and effective renal plasma flow (ERPF) through the action of insulin-like growth factor-I (IGF-I). We have measured clearance of inulin and para-aminohippuric acid in 18 children with chronic renal failure (CRF) during their 1st year of rhGH treatment to look at the immediate (first 3 h), short-term (1 week) and long-term (1 year) effects of treatment. On day 1 mean (range) age was 9.1 (4.9-13.9) years, GFR 19 (9-58) and ERPF 77 (34-271) ml/min per 1.73 m2. During treatment height velocity increased from 4.5 (1.7-6.5) to 9.5 (4.8-12.7) cm/year (P < 0.0001). Two children required dialysis after 0.75 years and 1 child was electively transplanted after 0.5 years. There were no other serious adverse events. GFR and ERPF were unchanged in the 3 h following rhGH. GFR remained constant on day 8, 22 (6-56) and after 1 year, 20 (9-59) ml/min per 1.73 m2. ERPF increased to 96 (33-276) ml/min per 1.73 m2 on day 8 (P = 0.005), and remained elevated, but not significantly so, at 99 (24-428) ml/min per 1.73 m2 at 1 year. Fasting IGF-I increased from 147 (46-315) ng/ml to 291 (61-673) by day 8 (P < 0.003), and to 341 (101-786) ng/ml at 1 year. There was no correlation between the change in IGF-I and renal function. Blood pressure, albumin excretion and dietary protein intake were unchanged by treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of dietary fatty acids in an animal model of focal glomerulosclerosis

The obese Zucker rat develops hyperlipidemia, proteinuria and focal glomerulosclerosis without prior changes in renal hemodynamics. To study the effects of oral fatty acid intake on the development of renal injury in this model, rats were fed standard chow or chow supplemented with either 14% fish oil or 14% beef tallow after unilateral nephrectomy at the age of 10 weeks. At 32 weeks post-nephrectomy animals were sacrificed and renal tissue saved to assess histology and glomerular eicosanoid production. Fish-oil treated rats had lower mean plasma cholesterol levels and developed less proteinuria than control or tallow-fed animals although there was no difference in plasma creatinine or blood pressure. Histological analysis showed significantly fewer sclerosed glomeruli in the fish oil group (4.0 +/- 0.8% vs. control 19.4 +/- 4.1%, P less than 0.0005 and vs. beef tallow 10.8 +/- 1.9%, P less than 0.005). Glomeruli derived from rats on fish oil supplements produced smaller amounts of prostaglandin (PG)E2 and of the stable metabolites of PGI2 (6-oxo-PGF1 alpha), PGF2 (PGF2 alpha) and thromboxane (TX)A2 (TXB2) than those from tallow-fed animals. This study demonstrates that oral fatty acid intake may influence the development of glomerulosclerosis. The apparent beneficial effects of fish oil have not been fully defined, but may relate to favorable changes in plasma lipid concentration and renal eicosanoid production.