Diagnosis and phenotypic assessment of Pakistani Haemophilia B carriers

Objectives:

1: To assess the diagnostic utility of three polymorphisms (DdeI, XmnI and TaqI) and direct sequencing in haemophilia B (HB) carrier detection in Pakistani families. 2: To compare phenotypes of HB carriers with those of healthy females.

Methods:

The study was conducted from March 2014 till February 2016 at Khyber Medical University Peshawar and National Institute of Blood Diseases, Karachi. Individuals from HB families of Khyber Pakhtunkhwa (KP) and Federally Administered Tribal Areas (FATA) with known F9 mutation in the proband were enrolled into the study. FIX activity (FIX: C) levels were determined in all the participants. Bleeding scores (BS) and complete blood counts were performed in the female participants. Linkage analysis followed by targeted Sanger sequencing was carried out in all the study participants. Heterozygosity rate was determined for each polymorphism. Healthy females and the carrier groups were compared for bleeding phenotypes.

Results:

A total of 30 males and 48 females from 13 HB families were studied. The polymorphisms had a low heterozygosity rate. Direct sequencing determined the carrier status in all cases. The mean FIX: C was reduced whereas BS was raised in the carriers when compared with healthy females. A significant raise in white blood cells (WBCs) count was observed in the carriers.

Conclusion:

The three polymorphisms have a low heterozygosity rate in HB families from KP and FATA. Sanger sequencing is conclusive in determining carrier status in all the cases. FIX: C is low and BS is raised in the HB carriers in comparison to that of normal females. The mean WBCs count is significantly higher in the HB carriers than the normal females.

Fucosyltransferase 2 (FUT2) non-secretor status and blood group B are associated with elevated serum lipase activity in asymptomatic subjects, and an increased risk for chronic pancreatitis: a genetic association study

OBJECTIVE

Serum lipase activities above the threefold upper reference limit indicate acute pancreatitis. We investigated whether high lipase activity-within the reference range and in the absence of pancreatitis-are associated with genetic single nucleotide polymorphisms (SNP), and whether these identified SNPs are also associated with clinical pancreatitis.

METHODS

Genome-wide association studies (GWAS) on phenotypes 'serum lipase activity' and 'high serum lipase activity' were conducted including 3966 German volunteers from the population-based Study-of-Health-in-Pomerania (SHIP). Lead SNPs associated on a genome-wide significance level were replicated in two cohorts, 1444 blood donors and 1042 pancreatitis patients.

RESULTS

Initial discovery GWAS detected SNPs within or near genes encoding the ABO blood group specifying transferases A/B (ABO), Fucosyltransferase-2 (FUT2), and Chymotrypsinogen-B2 (CTRB2), to be significantly associated with lipase activity levels in asymptomatic subjects. Replication analyses in blood donors confirmed the association of FUT-2 non-secretor status (OR=1.49; p=0.012) and ABO blood-type-B (OR=2.48; p=7.29×10(-8)) with high lipase activity levels. In pancreatitis patients, significant associations were found for FUT-2 non-secretor status (OR=1.53; p=8.56×10(-4)) and ABO-B (OR=1.69, p=1.0×10(-4)) with chronic pancreatitis, but not with acute pancreatitis. Conversely, carriers of blood group O were less frequently affected by chronic pancreatitis (OR=0.62; p=1.22×10(-05)) and less likely to have high lipase activity levels (OR=0.59; p=8.14×10(-05)).

CONCLUSIONS

These are the first results indicating that ABO blood type-B as well as FUT2 non-secretor status are common population-wide risk factors for developing chronic pancreatitis. They also imply that, even within the reference range, elevated lipase activities may indicate subclinical pancreatic injury in asymptomatic subjects.

Genetics of Psychosis in Alzheimer Disease

Psychosis occurs in approximately half of patients with Alzheimer disease (AD with psychosis, AD+P). AD+P patients have more rapid cognitive decline, greater behavioral symptoms, and higher mortality than do AD patients without psychosis. Studies in three independent cohorts have shown that psychosis in AD aggregates in families, with estimated heritability of 29.5 - 60.8%. These findings have motivated studies to investigate and uncover the genes responsible for the development of psychosis, with the ultimate goal of identifying potential biologic mechanisms that may serve as leads to specific therapies. Linkage analyses have implicated loci on chromosomes 2, 6, 7, 8, 15, and 21 with AD+P. Association studies of APOE do not support it as a risk gene for psychosis in AD. No other candidate genes, such as neurodegenerative and monoamine genes, show conclusive evidence of association with AD+P. However, a recent genome-side association study has produced some promising leads, including among them genes that have been associated with schizophrenia. This review summarizes the current knowledge of the genetic basis of AD+P.