Association between polymorphism rs2032487 in the non-muscle myosin heavy chain IIA gene (MHY9) and chronic kidney disease secondary to type 2 diabetes mellitus in a population of the Canary Islands

The Potential Impact of MYH9 (rs3752462) and ELMO1 (rs741301) Genetic Variants on the Risk of Nephrotic Syndrome Incidence

The kidney lost a lot of protein in the urine when you have nephrotic syndrome (NS). Clinical manifestations mostly common in NS include massive proteinuria, hypoalbuminemia, hyperlipidemia, and edema. Idiopathic nephrotic syndrome is currently classified into steroid-dependent (SDNS) and steroid-resistant (SRNS) based on the initial response to corticosteroid therapy at presentation. Several reports examined the association of the MYH9 gene (rs3752462, C > T) variant and ELMO1 gene (rs741301 G > A) variant as risk factors for Nephrotic Syndrome. This study aimed to determine the potential effect of the MYH9 gene (rs3752462, C > T) and ELMO1 gene (rs741301) variant on the risk of (NS) among Egyptian Children. This study included two hundred participants involving 100 nephrotic syndrome (NS) cases and 100 healthy controls free from nephrotic syndrome (NS). The MYH9 gene (rs3752462, C > T) variant and ELMO1 gene (rs G > A741301) variant were analyzed by ARMS-PCR technique. Nephrotic syndrome cases include 74% SRNS and 26% SDNS. Higher frequencies of the heterozygous carrier (CT) and homozygous variant (TT) genotypes of the MYH9 (rs3752462, C > T) variant were observed in NS patients compared to the controls with p-value < 0.001. The frequencies of the MYH9 (rs3752462, C > T variant indicated a statistically significant elevated risk of NS under various genetic models, including allelic model (OR 2.85, p < 0.001), dominant (OR 3.97, p < 0.001) models, and the recessive model OR 5.94, p < 0.001). Higher frequencies of the heterozygous carrier (GA) and homozygous variant (AA) genotypes of ELMO1gene (rs G > A741301) variant were observed in NS patients compared to the controls with p-value < 0.001. The frequencies of the ELMO1 (rs G > A741301) variant indicated a statistically significant elevated risk of NS under various genetic models, including allelic model (OR 2.15, p < 0.001), dominant models (OR 2.8, p < 0.001), and the recessive model (OR 4.17, p = 0.001). Both MYH9 and ELMO1 gene variants are significantly different in NS in comparison with the control group (p < 0.001). The MYH9 gene (rs3752462, C > T) and ELMO1gene (rs G > A741301) variants were considered independent risk factors for NS among Egyptian Children.

Association of MYH9-rs3752462 polymorphisms with chronic kidney disease among clinically diagnosed hypertensive patients: a case-control study in a Ghanaian population

Background

Chronic kidney disease (CKD) is a significant comorbidity among hypertensive patients. Polymorphisms in the non-muscle myosin heavy chain 9 gene (MYH9) have been demonstrated to be significantly associated with CKD, among African- and European-derived populations. We investigated the spectrum of MYH9-associated CKD among Ghanaian hypertensive patients.

Methods

The study constituted a total of 264 hypertensive patients. Hypertensive patients with glomerular filtration rate (eGFR) < 60 ml/min/1.73m² (CKD-EPI formula) or clinically diagnosed were defined as case subjects (n = 132) while those with eGFR ≥60 ml/min/1.73m² were classified as control subjects (n = 132). Demographic data were obtained with a questionnaire and anthropometric measurements were taken. Five (5) millilitres (ml) of venous blood was drawn from study subjects into gel and EDTA vacutainer tubes. Two (2) mL of EDTA anticoagulated blood was used for genomic DNA extraction while three (3) mL of blood was processed to obtain serum for biochemical measurements. Genotyping of MYH9 polymorphisms (rs3752462) was done employing Tetra primer Amplification Refractory Mutation System (T-ARMS) polymerase chain reaction (PCR). Spot urine samples were also collected for urinalysis. Hardy-Weinberg population was assessed. Logistic regression models were used to assess the associations between single nucleotide polymorphisms and CKD.

Results

The cases and control participants differed in terms of age, sex, family history, and duration of CKD (p-value < 0.001). The minor allele frequencies of rs3752462 SNP were 0.820 and 0.567 respectively among the control and case subjects. Patients with the heterozygote genotype of rs3752462 (CT) were more likely to develop CKD [aOR = 7.82 (3.81–16.04)] whereas those with homozygote recessive variant (TT) were protective [aOR = 0.12 (0.06–0.25)]. Single nucleotide polymorphism of rs3752462 (CT genotype) was associated with increased proteinuria, albuminuria, and reduced eGFR.

Conclusions

We have demonstrated that MYH9 polymorphisms exist among Ghanaian hypertensive patients and rs3752462 polymorphism of MYH9 is associated with CKD. This baseline indicates that further longitudinal and multi-institutional studies in larger cohorts in Ghana are warranted to evaluate MYH9 SNP as an independent predictor of CKD among hypertensive patients in Ghana.

MYH9-related disease: it does exist, may be more frequent than you think and requires specific therapy

In this issue of ckj, Tabibzadeh et al. report one of the largest series of patients with MYH9 mutations and kidney disease. The cardinal manifestation of MYH9-related disease is thrombocytopenia with giant platelets. The population frequency of pathogenic MYH9 mutations may be at least 1 in 20 000. The literature abounds in misdiagnosed cases treated for idiopathic thrombocytopenic purpura with immune suppressants and even splenectomy. Additional manifestations include neurosensorial deafness and proteinuric and hematuric progressive kidney disease (at some point, it was called Alport syndrome with macrothrombocytopenia), leucocyte inclusions, cataracts and liver enzyme abnormalities, resulting in different names for different manifestation combinations (MATINS, May-Hegglin anomaly, Fechtner, Epstein and Sebastian syndromes, and deafness AD 17). The penetrance and severity of kidney disease are very variable, which may obscure the autosomal dominant inheritance. A correct diagnosis will both preclude unnecessary and potentially dangerous therapeutic interventions and allow genetic counselling and adequate treatment. Morphological erythrocyte, granulocyte and platelet abnormalities may allow the future development of high-throughput screening techniques adapted to clinical peripheral blood flow cytometers.