Crystalline gene mutations in Turkish children with congenital cataracts.

PURPOSE: To detect crystallin gene mutations in Turkish children with congenital cataracts. METHODS: The present study included 56 children (38 males and 18 females) who were diagnosed with congenital cataract in our ophthalmology clinic. The patients' blood samples were collected and sent to the medical genetics laboratory. The samples were assessed using the sequence analysis method, which covered all exons of CRYAA, CRYAB, CRYBB1, CRYBB2, CRYBB3, CRYGC and CRYGD. RESULTS: In total, 56 patients with congenital cataracts were included in the present study. Of these, 68% were male and 32% were female. The age range of the patients was 2 months to 5 years. The mean age of onset was 21.08 ± 15.15 months. All the patients had bilateral congenital cataracts. The female-to-male ratio was 1:2.1. Mutation analysis was performed to detect possible mutations in CRYAA, CRYAB, CRYBB1, CRYBB2, CRYBB3, CRYGC and CRYGD. Of the four mutations detected, one was novel (c.383A > T in CRYGD) and three were known (c.592C > T in CRYBB2, c.164A > G in CRYGC and c.592C > T in CRYBB2). Two of these three mutations were detected in the same gene (CRYBB2). Crystallin gene mutations were detected in 7% of patients with congenital cataracts (four out of 56 patients) in the present study. CONCLUSIONS: We think that mutations in crystallin genes are responsible for 7% of congenital cataract cases in our country. The detection of these mutations may help in the molecular diagnosis of congenital cataracts.

Early-infantile onset epilepsy and developmental delay caused by bi-allelic GAD1 variants.

Gamma-aminobutyric acid (GABA) and glutamate are the most abundant amino acid neurotransmitters in the brain. GABA, an inhibitory neurotransmitter, is synthesized by glutamic acid decarboxylase (GAD). Its predominant isoform GAD67, contributes up to ∼90% of base-level GABA in the CNS, and is encoded by the GAD1 gene. Disruption of GAD1 results in an imbalance of inhibitory and excitatory neurotransmitters, and as Gad1-/- mice die neonatally of severe cleft palate, it has not been possible to determine any potential neurological dysfunction. Furthermore, little is known about the consequence of GAD1 disruption in humans. Here we present six affected individuals from six unrelated families, carrying bi-allelic GAD1 variants, presenting with developmental and epileptic encephalopathy, characterized by early-infantile onset epilepsy and hypotonia with additional variable non-CNS manifestations such as skeletal abnormalities, dysmorphic features and cleft palate. Our findings highlight an important role for GAD1 in seizure induction, neuronal and extraneuronal development, and introduce GAD1 as a new gene associated with developmental and epileptic encephalopathy.

Clinical characteristics and molecular genetic analysis of 22 patients with neonatal diabetes from the South-Eastern region of Turkey: predominance of non-KATP channel mutations.

BACKGROUND: Neonatal diabetes mellitus (NDM) is a rare form of monogenic diabetes and usually presents in the first 6 months of life. We aimed to describe the clinical characteristics and molecular genetics of a large Turkish cohort of NDM patients from a single centre and estimate an annual incidence rate of NDM in South-Eastern Anatolian region of Turkey. DESIGN AND METHODS: NDM patients presenting to Diyarbakir Children State Hospital between 2010 and 2013, and patients under follow-up with presumed type 1 diabetes mellitus, with onset before 6 months of age were recruited. Molecular genetic analysis was performed. RESULTS: Twenty-two patients (59% males) were diagnosed with NDM (TNDM-5; PNDM-17). Molecular genetic analysis identified a mutation in 20 (95%) patients who had undergone a mutation analysis. In transient neonatal diabetes (TNDM) patients, the genetic cause included chromosome 6q24 abnormalities (n=3), ABCC8 (n=1) and homozygous INS (n=1). In permanent neonatal diabetes (PNDM) patients, homozygous GCK (n=6), EIF2AK3 (n=3), PTF1A (n=3), and INS (n=1) and heterozygous KCNJ11 (n=2) mutations were identified. Pancreatic exocrine dysfunction was observed in patients with mutations in the distal PTF1A enhancer. Both patients with a KCNJ11 mutation responded to oral sulphonylurea. A variable phenotype was associated with the homozygous c.-331C>A INS mutation, which was identified in both a PNDM and TNDM patient. The annual incidence of PNDM in South-East Anatolian region of Turkey was one in 48 000 live births. CONCLUSIONS: Homozygous mutations in GCK, EIF2AK3 and the distal enhancer region of PTF1A were the commonest causes of NDM in our cohort. The high rate of detection of a mutation likely reflects the contribution of new genetic techniques (targeted next-generation sequencing) and increased consanguinity within our cohort.

Association between A/C1166 gene polymorphism of the angiotensin II type 1 receptor and biventricular functions in patients with acute myocardial infarction.

BACKGROUND: Although there have been several association studies of angiotensin II type 1 receptor (AT1R, A/C1166) gene polymorphism in clinical endpoints such as myocardial infarction (MI), hypertension, aortic stiffness, and left ventricular mass, the relationship between AT1R polymorphism and biventricular function in acute anterior MI has not been studied before. METHODS AND RESULTS: The study group comprised 132 consecutive patients who were admitted to the coronary care unit with their first acute anterior MI. Systolic and diastolic diameters, volumes, inflow properties, ejection fraction and myocardial performance index of both ventricles were measured. AT1R polymorphism was determined using polymerase chain reaction amplification. Based on A/C1166 polymorphism of AT1R, the patients were classified into 3 groups: group 1, A/A (n=91) genotype, group 2 A/C (n=28), and group 3 C/C (n=13) genotype. When the left ventricular and right ventricular echocardiographic functions were compared, all parameters of the 3 groups were found to be similar. No difference was detected in either the genotype distribution or allele frequencies between the patients and the controls for AT1R. CONCLUSIONS: The results suggest that A/C1166 polymorphism of AT1R did not influence the risk of either acute MI or biventricular function after anterior MI.

Angiotensin-converting enzyme and angiotensin II type 1 receptor gene polymorphisms in children with subacute sclerosing panencephalitis.

Subacute sclerosing panencephalitis (SSPE) is a progressive, debilitating, and fatal brain disorder caused by mutant measles virus infection. Although both viral and host factors seem to be involved in SSPE, the exact pathogenesis remains to be determined. Autoimmune demyelination is characteristic of SSPE. The blood angiotensin-converting enzyme (ACE) activity and angiotensin II (Ang II) levels are associated with the ACE gene polymorphism. Proinflammatory effects of Ang II may contribute to the development of SSPE. The aim of this study was to investigate whether the ACE and Ang II type 1 receptor (AT1R) (A1166C) gene polymorphisms were associated with SSPE. The polymorphisms were investigated by polymerase chain reaction (PCR) in 43 patients with SSPE and 100 healthy controls. The genotype distribution of the SSPE children and healthy controls were as follows: DD 58.1% versus 34.0, ID 37.2% versus 48.0%, and II 4.7% versus 18.0, respectively (P = 0.012). Allele frequencies of patients and controls were D 76.7% versus 58.0%, and I 23.3% versus 42.0%, respectively (P = 0.004). The frequency of DD genotype and D allele were significantly higher in SSPE children compared with controls (P < 0.05). AT1R gene polymorphism distribution was found to be similar in SSPE children and control subjects: AA 55.8% versus 60.7%, AC 37.2% versus 32.1%, and CC 7.0% versus 7.2%, respectively (P > 0.05). In conclusion, the results of this study suggest that the DD genotype of ACE I/D polymorphism may be related to SSPE. Due to small size of this study, further studies with more patients are needed to confirm these results.

Prevalence of occult HBV infection in haemodialysis patients with chronic HCV.

AIM: To study the prevalence and clinical effects of occult HBV infection in haemodialysis patients with chronic HCV. METHODS: Fifty chronic hemodialysis patients with negative HbsAg, and positive anti-HCV were included in the study. These patients were divided into two groups: HCV-RNA positive and HCV-RNA negative, based on the results of HCV-RNA PCR. HBV-DNA was studied using the PCR method in both groups. RESULTS: None of the 22 HCV-RNA positive patients and 28 HCV-RNA negative patients revealed HBV-DNA in serum by PCR method. The average age was 47.2 +/- 17.0 in the HCV-RNA positive group and 39.6 +/- 15.6 in the HCV-RNA negative group. CONCLUSION: The prevalence of occult HBV infection is not high in haemodialysis patients with chronic HCV in our region. This result of our study has to be evaluated in consideration of the interaction between HBsAg positivity (8%-10%) and frequency of HBV mutants in our region.

Polymorphisms of the angiotensin converting enzyme and angiotensin II type 1 receptor genes and renal scarring in non-uropathic children with recurrent urinary tract infection.

AIM: The aim of this study was to investigate whether the angiotensin converting enzyme (ACE) and angiotensin II type 1 receptor (A1166C) gene polymorphisms were associated with the renal scar formation secondary to recurrent urinary tract infection in children without uropathy. METHODS: The polymorphisms were investigated by polymerase chain reaction in 97 children (81 females, 16 males; age, 2.5-13 years) with recurrent urinary tract infection and 100 healthy controls as a single centre study. Children with vesicoureteral reflux, bladder dysfunction and other uropathies were excluded. The dimercaptosuccinic acid (DMSA) scan performed at least 3 months after a proven urinary tract infection and the result of the last DMSA was taken into consideration. RESULTS: Renal scarring was found in 30 patients (30.9%) using DMSA scan. The number of urinary tract infection attacks was significantly higher in patients with renal scarring compared with children without scarring (P<0.05). The follow-up period and male/female ratio of patients with or without renal scarring was similar (P>0.05). Age at the first urinary tract infection was lower in the group with scarring. The ACE insertion/deletion genotype distribution and D allele frequency were similar between patients and controls (P>0.05), and in patients with renal scarring and those without renal scarring. Also, the angiotensin II type 1 receptor gene polymorphism was not associated with renal parenchymal damage (P>0.05). CONCLUSION: The results indicated that the ACE insertion/deletion and angiotensin II type 1 receptor gene polymorphisms were not independent risk factors for renal scar formation in recurrent urinary tract infection of paediatric patients without uropathy.

Influence of angiotensin-converting enzyme I/D gene polymorphism on the right ventricular myocardial performance index in patients with a first acute anterior myocardial infarction.

BACKGROUND: The genetic influence on the myocardial performance index is uncertain, so the aim of the present study was to determine the effects of polymorphism of the angiotensin-converting enzyme (ACE) gene on the right ventricular myocardial performance index (RVMPI) after a first acute anterior myocardial infarction (MI). METHODS AND RESULTS: The subjects were 116 patients with a first acute anterior MI. Based on the polymorphism of the ACE gene, they were classified into 3 groups: deletion/deletion (DD) genotype (group 1, n=45), insertion/deletion (ID) genotype (group 2, n=58), insertion/insertion (II) genotype (group 3, n=13). Echocardiograms were used to determine the RVMPI, left ventricular myocardial performance index (LVMPI), tricuspid E/A, tricuspid deceleration time and the left ventricular diameter diastolic and diameter systolic (LVDd and LVDs). RVMPI and LVMPI were significantly higher in the ACE DD group. Tricuspid E/A, DT, LVDd and LVDs showed no differences among the 3 groups. CONCLUSION: The ID polymorphism of the ACE gene may affect RVMPI and LVMPI after a first acute anterior MI.

Determination of serum hepatitis B virus DNA in chronic HBsAg carriers: clinical significance and correlation with serological markers.

BACKGROUND/AIMS: Hepatitis B virus infection is among the most devastating health problems in the world, including Turkey. In this cross-sectional study, we aimed to investigate the correlations between hepatitis B virus genomic load and various measures of the progression of chronic hepatitis B virus infection. METHODS: A total of 354 chronic HBsAg carriers [126 inactive HBsAg carriers, 50 asymptomatic replicative carriers (immune tolerant patients), 90 chronic hepatitis B patients and 88 patients with liver cirrhosis] were enrolled into the study. Eligible patients included males and females, 14-62 years of age, with detectable serum HBsAg, HBeAg or anti-HBe in serum at the time of screening and for at least six months before study entry. Serum hepatitis B virus DNA was detected by liquid hybridization, and results under the level of 1 pg/ml were additionally confirmed by polymerase chain reaction. RESULTS: Of 354 patients, 118 (33%) were HBeAg-positive and 236 (67%) HBeAg-negative. Of HBeAg-negative patients, 126 (53%) had normal alanine aminotransferase, 31 (13%) had elevated alanine aminotransferase (chronic hepatitis B) and 79 (33%) had evidence of cirrhosis; corresponding figures in the HBeAg-positive patients were 50 (42%), 59 (50%) and 9 (8%). There is a significant correlation between transaminase values and histological liver damage, whereas no correlation was found between viral replication and liver damage. CONCLUSIONS: Hepatitis B virus DNA is an important and specific marker for ongoing hepatitis B virus related liver disease, but alanine aninotransferase was shown to be the best marker for liver inflammation and not hepatitis B virus viral load. Although these findings are not new, they are of some utility since they prevent unnecessary and cost-intensive viral load determinations in chronic HBsAg carriers.

The lack of effect of therapeutic vaccination with a pre-S2/S HBV vaccine in the immune tolerant phase of chronic HBV infection.

BACKGROUND/AIMS: Even if the results are controversial and preliminary, several reports suggest that the HBV vaccine might be effective in treating HBV infection. In this study, we aimed to evaluate the efficacy and safety of specific anti-HBV vaccination for the immune tolerance phase of chronic HBV infection in a randomized, controlled study. PATIENTS AND METHODS: The 47 subjects included patients that were treatment-naive with hepatitis B e antigen positivity, active hepatitis B virus replication as measured by hepatitis B virus DNA levels, persistently normal alanine transaminase levels, and with minimal or absent disease activity by liver biopsy. Thirty patients were given three intramuscular injections of 20 micro g of a pre-S2/S vaccine (GenHevac-B) on days 0, 30, and 60, and the remaining 17 patients were included in the control group. The efficacy of vaccination was evaluated by testing for loss of serum HBV DNA or decrease in its level and for HBeAg seroconversion. A significant decrease in HBV DNA levels was accepted as a decrease of >50% of initial values. The complete response was defined as loss of HBV DNA in serum with HBeAg seroconversion. Postvaccination follow-up lasted 12 months after the first dose. RESULTS: No significant effects were observed in the vaccination population in the reduction of HBV DNA to undetectable levels, or to <50% of prevaccination levels, in HBeAg/anti-HBe seroconversion, or in transaminase levels. There was an early clearance/decrease in HBV DNA levels in five vaccinated patients by 3 months, and none in controls (P = 0.143), and two of them had sustained responses later. At the end of follow-up, complete response is almost similar in study as well as control group (13% vs. 12%, P > 0.05). Disappearance of serum HBV DNA was more frequently observed in those patients who had pretreatment viremia of <100 pg/mL in both groups. The median levels of HBV DNA and alanine transaminase activity between baseline and 12 months did not differ significantly in both groups. All patients remained HBsAg positive and none developed anti-HBs. No serious adverse event was encountered in vaccinated patients, and the therapy was well tolerated. Follow-up lasted a median of 16 months (range 12-30 months) for the study group and 18 months (range 12-31months) for the control group. CONCLUSIONS: Immunotherapy with specific anti-HBV vaccine in the immune tolerance phase of chronic HBV infection did not offer additional benefit. New immunotherapeutic strategies to control HBV infection by specific HBV vaccines in chronically infected subjects are needed.