Genetic polymorphisms of PIP5K2A and course of schizophrenia

A novel gain-of-function PIP4K2A mutation elevates the expression of β-globin and aggravates the severity of α-thalassemia

Haemoglobin H (Hb H) disease (intermediate status of α-thalassemia) shows marked phenotypic variability from asymptomatic to severe anaemia. Apart from the combined β-thalassemia allele ameliorating clinical severity, reports of genetic modifier genes affecting the phenotype of Hb H disease are scarce which bring inconvenience to precise diagnosis and genetic counselling of the patients. Here, we present a novel mutation (c.948C>A, p.S316R) in the PIP4K2A gene in a female Hb H disease patient who displayed moderate anaemia and a relatively high Hb H level. Haematological analysis in her family members revealed that individuals carrying this mutation have upregulated β-globin expression, leading to a more imbalanced β/α-globin ratio and more Hb H inclusion bodies in peripheral red blood cells. According to functional experiments, the mutant PIP4K2A protein exhibits enhanced protein stability, increased kinase activity and a stronger regulatory effect on downstream proteins, suggesting a gain-of-function mutation. Moreover, introduction of the S316R mutation into HUDEP-2 cells increased expression of β-globin, further inhibiting erythroid differentiation and terminal enucleation. Thus, the S316R mutation is a novel genetic factor associated with β-globin expression, and the PIP4K2A gene is a new potential modifier gene affecting the α-thalassemia phenotype.

Polymorphisms of the BCL2 gene associated with susceptibility to tuberculosis

Although tuberculosis (TB) is a serious public health concern, we still don’t understand why only 10% of people infected will develop the disease. Apoptosis plays a role in the interaction of Mycobacterium tuberculosis (Mtb) with the human host and it may be modified by subtle alterations in the B-cell lymphoma 2 (BCL2) gene, an anti-apoptotic regulatory element. Therefore, we investigated whether there is an association between BCL2 polymorphisms and susceptibility to TB by analyzing 130 TB cases, 108 subjects with latent TB infection (LTBI), and 163 healthy controls (HC). Logistic regression was used to calculate odds ratios (ORs) and 95% confidential intervals (95% CIs) for possible associations between single nucleotide polymorphisms (SNPs) in BCL2 and the risk of tuberculosis. We found that the G allele of rs80030866 (OR=0.62, 95%CI:0.42-0.91, P=0.015), and also the G allele of rs9955190 (OR=0.58, 95%CI:0.38-0.88, P=0.011) were less frequent in the TB group compared with the LTBI group. In addition, individuals with rs2551402 CC genotype were more likely to have LTBI than those with AA genotype (OR=2.166, 95%CI:1.046-4.484, P=0.037). Our study suggests that BCL2 gene polymorphisms may be correlated with susceptibility to both TB and LTBI.