POU3F3-related disorder: Defining the phenotype and expanding the molecular spectrum.

POU3F3 variants cause developmental delay, behavioral problems, hypotonia and dysmorphic features. We investigated the phenotypic and genetic landscape, and genotype-phenotype correlations in individuals with POU3F3-related disorders. We recruited unpublished individuals with POU3F3 variants through international collaborations and obtained updated clinical data on previously published individuals. Trio exome sequencing or single exome sequencing followed by segregation analysis were performed in the novel cohort. Functional effects of missense variants were investigated with 3D protein modeling. We included 28 individuals (5 previously published) from 26 families carrying POU3F3 variants; 23 de novo and one inherited from an affected parent. Median age at study inclusion was 7.4 years. All had developmental delay mainly affecting speech, behavioral difficulties, psychiatric comorbidities and dysmorphisms. Additional features included gastrointestinal comorbidities, hearing loss, ophthalmological anomalies, epilepsy, sleep disturbances and joint hypermobility. Autism, hearing and eye comorbidities, dysmorphisms were more common in individuals with truncating variants, whereas epilepsy was only associated with missense variants. In silico structural modeling predicted that all (likely) pathogenic variants destabilize the DNA-binding region of POU3F3. Our study refined the phenotypic and genetic landscape of POU3F3-related disorders, it reports the functional properties of the identified pathogenic variants, and delineates some genotype-phenotype correlations.

Three Afghani siblings with a novel homozygous variant and further delineation of the clinical features of METTL5 related intellectual disability syndrome.

BACKGROUND: METTL5 gene is one of the members of methyltransferase superfamily and biallelic variants cause intellectual disability syndrome (ID) with microcephaly. This article reports three new cases with METTL5 related ID syndrome in a consanguineous family. CASE: Afghanistan descent family was affected by a novel homozygous c.362A > G (p.Asp121Gly) METTL5 gene variant. This variant is predicted to be `pathogenic` by multiple in-silico tools. Patients had dysmorphic and neurodevelopmental features including intellectual disability, microcephaly, poor/absent speech, delayed walking, aggressive behavior, large/posteriorly rotated ears, broad nasal base and short stature, which seem to be the cardinal findings of the designated syndrome. CONCLUSIONS: While the data reported in these individuals indicate characteristic clinical features of METTL5 related ID syndrome, further investigations and study of additional cases are needed to improve the understanding of disease pathogenesis, and management.

Coexistence of severe developmental delay, epilepsy, and hemangioma in Snijders Blok-Fisher syndrome suggests the presence of a POU3F3-related SNIBFIS endophenotype: A case report.

POU3F3 proteins are eukaryotic transcription factors and contribute to the processes in the development of brain and kidney. Pathogenic POU3F3 variants cause a neurodevelopmental disorder called Snijders Blok-Fisher syndrome (SNIBFIS). This article reports a new SNIBFIS case harboring a novel heterozygous c.1018_1019delCAinsTT (p.Gln340Leu) variant in the POU3F3 gene. This variant affects the α2 helix of POU-S domain and is predicted to be "pathogenic" by multiple in-silico tools. The proband had severe intellectual disability, hypotonia, autistic features, sleep disturbances, and dysmorphic features. The association with epilepsy and hemangioma like two of the three previously reported patients with mutations in the POU-S domain was also a remarkable finding to understand the importance of POU-S domain. This clinical report also highlights the interest of reinterpretation of molecular data and brings a new perspective to the genotype-phenotype relationship in "Snijders Blok-Fisher syndrome".

Carbonic anhydrase VA deficiency: a very rare case of hyperammonemic encephalopathy.

Objectives Carbonic anhydrase VA (CAVA) deficiency is a rare autosomal recessive inborn error of metabolism that leads to acute metabolic crises, especially in the neonatal or infantile period. It is caused by a deficiency of the enzyme CAVA, which is encoded by the CA5A gene. Case presentation Fifteen patients with homozygous pathogenic CA5A mutations involving 10 different lesions have been reported in the literature up to date. Main clinical and biochemical features of CAVA deficiency include lethargy, hyperammonemic encephalopathy, metabolic acidosis, elevated lactate and hypoglycemia. In most patients reported so far, a single metabolic decompensation attack has been reported, and they have remained stable thereafter with no further crisis. Conclusions We report the 16th case of CAVA deficiency, who was diagnosed by whole-exome sequencing and showed a typical course of the disease with normal development at 18 months.

Increased Endothelial Dysfunction and Insulin Resistance in Patients with Klinefelter Syndrome.

BACKGROUND AND OBJECTIVE: Patients with Klinefelter Syndrome (KS) have increased cardiometabolic risk however the pathogenesis is not clear. We investigated the presence of endothelial dysfunction, insulin resistance and inflammation in an unconfounded population of KS. METHODS: A total of 32 patients with KS (mean age 21.59 ± 1.66 years) and 33 healthy control subjects (mean age: 22.15 ± 1.03 years) were enrolled. The demographic parameters, Asymmetric dimethylarginine (ADMA), homeostatic model assessment of insulin resistance (HOMA-IR) index and highsensitivity C-reactive protein (hs-CRP) levels were measured. RESULTS: The patients had higher Follicle Stimulating Hormone (FSH), Luteinizing Hormone (LH), insulin, HOMA-IR and ADMA levels (p < 0.001 for all) and lower High Density Lipoprotein Cholesterol (HDL-C) and total testosterone levels (p=0.002 and p<0.001, respectively), compared to the healthy controls. Total testosterone levels were significantly negatively correlated to ADMA (r = - 0.479, p < 0,001), hs-CRP (r = -0.291, p = 0.034) and positively correlated to HDL-C (r = 0.429, p = 0.001) levels. The multivariate analysis has shown that total testosterone (ß = -0.412, p = 0.001) and TG (ß = 0.332, p = 0.009) levels were the significant independent determinants of the plasma ADMA levels. CONCLUSION: The results of the present study show that endothelial dysfunction and insulin resistance are prevalent even in the very young subjects with KS, who have no metabolic or cardiac problems at present. Also, hypogonadism seems to play an important role for increased cardiometabolic risk in patients with KS.

Effects of triethylene glycol dimethacrylate (TEGDMA) on the odontoclastic differentiation ability of human dental pulp cells.

OBJECTIVES: The primary purpose of this study was to examine the effects of triethylene glycol dimethacrylate (TEGDMA) on odontoclastic differentiation in the dental pulp tissue. MATERIAL AND METHODS: The effects of different TEGDMA dosages on the odontoclastic differentiation capability of dental pulp cells were analyzed in vitro using the following methodologies: i) flow cytometry and tartrate-resistant acid phosphatase (TRAP) staining; ii) apoptotic effects using Annexin V staining; iii) mRNA expression of osteoprotegerin (OPG) and receptor activator of nuclear factor (NF)-kB ligand (RANKL) genes by quantitative Real-time PCR (qRT-PCR); and iv) OPG and RANKL protein expression by enzyme-linked immunosorbent assay (ELISA). RESULTS: TEGDMA caused relatively less odontoclastic differentiation in comparison with the control group; however, odontoclastic differentiation augmented with increasing doses of TEGDMA (p<0.05). The mRNA and protein expression of OPG was lower in TEGDMA treated pulp cells than in the control group (p<0.05). While the mRNA expression of RANKL remained unchanged compared to the control group (p>0.05), its protein expression was higher than the control group (p<0.05). In addition, TEGDMA increased the apoptosis of dental pulp cells dose dependently. CONCLUSIONS: TEGDMA reduced the odontoclastic differentiation ability of human dental pulp cells. However, odontoclastic differentiation ratios increased proportionally with the increasing dose of TEGDMA.

Effects of triethylene glycol dimethacrylate (TEGDMA) on the odontoclastic differentiation ability of human dental pulp cells

Abstract Objectives: The primary purpose of this study was to examine the effects of triethylene glycol dimethacrylate (TEGDMA) on odontoclastic differentiation in the dental pulp tissue. Material and Methods: The effects of different TEGDMA dosages on the odontoclastic differentiation capability of dental pulp cells were analyzed in vitro using the following methodologies: i) flow cytometry and tartrate-resistant acid phosphatase (TRAP) staining; ii) apoptotic effects using Annexin V staining; iii) mRNA expression of osteoprotegerin (OPG) and receptor activator of nuclear factor (NF)-kB ligand (RANKL) genes by quantitative Real-time PCR (qRT-PCR); and iv) OPG and RANKL protein expression by enzyme-linked immunosorbent assay (ELISA). Results: TEGDMA caused relatively less odontoclastic differentiation in comparison with the control group; however, odontoclastic differentiation augmented with increasing doses of TEGDMA (p<0.05). The mRNA and protein expression of OPG was lower in TEGDMA treated pulp cells than in the control group (p<0.05). While the mRNA expression of RANKL remained unchanged compared to the control group (p>0.05), its protein expression was higher than the control group (p<0.05). In addition, TEGDMA increased the apoptosis of dental pulp cells dose dependently. Conclusions: TEGDMA reduced the odontoclastic differentiation ability of human dental pulp cells. However, odontoclastic differentiation ratios increased proportionally with the increasing dose of TEGDMA.

Association of retinal vein occlusion, homocysteine, and the thrombophilic mutations in a Turkish population: A case-control study.

PURPOSE: To compare homocysteine and thrombophilic mutations for the methylenetetrahydrofolate reductase (MTHFR) C677T, factor V Leiden, and prothrombin G20210A between retinal vein occlusion (RVO) and healthy controls in a Turkish population. MATERIALS AND METHODS: Forty-nine subjects with RVO were compared for homocysteine status and the MTHFR C677T, prothrombin G20210A, and factor V Leiden mutations with those of 68 healthy controls. Then, the groups were subdivided into two subgroups according to age (less than 50 years old, equal to or more than 50 years old) and were further compared. RESULTS: Mean plasma level of homocysteine was similar, but the frequency of hyperhomocysteinemia was significantly higher in the RVO group when compared with the control group (22.5% and 8.8%, respectively, p = 0.037). The frequency of all thrombophilic mutations was similar between the groups (p > 0.05). The frequency of all thrombophilic mutations and homocysteine levels was also similar between age subgroups (p > 0.05). Only hyperhomocysteinemia was significantly different between subgroups (p = 0.037); the frequency of hyperhomocysteinemia was significantly different in RVO patients less than 50 years old (22.7%) from that in healthy controls less than 50 years old (11.1%). Two RVO patients (4.1%) with bilateral involvement had MTHFR C677T mutation. CONCLUSIONS: Screening for thrombophilic mutations such as MTHFR C677T, factor V Leiden, and prothrombin G20210A in RVO patients at all ages seems to be unnecessary and not cost-effective. However, thrombophilic disorders should be screened selectively, focusing on young individuals, especially with bilateral involvement, without additional cardiovascular risk factors, or a family history of thrombosis.

Gene expression changes in bioceramic paste-treated human dental pulp cells.

We evaluated the gene expression profiles of human dental pulp cells exposed to iRoot BP using microarray after 24 and 72 h. The results were verified using quantitative reverse transcriptase PCR analysis. Of the 36,000 transcripts arrayed, 21 were up-regulated and 15 were down-regulated by more than two fold. The largest group of up-regulated genes included those involved in nucleobase-containing compound metabolic processes, cell communication, protein metabolic processes, developmental processes, and biological regulation. The largest groups of down-regulated genes were those involved in cell communication, development, and biological regulation processes. In conclusion, iRoot BP affects the expression of genes involved in different biological processes in human dental pulp cells. (J Oral Sci 58, 307-315, 2016).

Hypoxia inhibits mineralization ability of human dental pulp cells treated with TEGDMA but increases cell survival in accordance with the culture time.

OBJECTIVE: To evaluate the cytotoxicity and mineralization effects of TEGDMA in human dental pulp cells (hDPCs) under hypoxic and normoxic culture conditions. DESIGN: Cell viability was evaluated using XTT assay after incubation periods of 24, 48, or 72h. The expression of mineralization-related genes (osteonectin, osteopontin, dentin sialophosphoprotein, collagen type 1) and heme oxygenase 1 (HO-1) was assessed by quantitative real-time polymerase chain reaction at 24 and 72h. RESULTS: In XTT assay, viability was higher in 0.3, 1, 2, 4, and 5mM groups in the presence of 21% O2 after 24h (p<0.05). Additionally, while 0.3, 1, 2mM groups had higher cell viability in the presence of 21% O2 after 48h (p<0.05), in 3mM groups cell viability was higher under 3% O2 than 21% O2 after both 24 and 48h (p<0.05). 1-3mM groups had higher cell viability under 3% O2 after 72h (p<0.05). There was no difference between 4 and 5mM groups with regards to cell viability after 48 or 72h (p>0.05). In the gene expression study, TEGDMA-treated hDPCs showed lower mineralization potential in the presence of 3% than with 21% O2 (p<0.05). hDPCs revealed higher HO 1 expression in 0.3 and 1mM groups under hypoxic than under normoxic conditions after a 72-h time period (p<0.001). CONCLUSIONS: Hypoxic conditions increased cell survival in accordance with the culture period but inhibited the odontoblastic differentiation of hDPCs treated with TEGDMA.

Molecular etiology of arthrogryposis in multiple families of mostly Turkish origin.

BACKGROUND: Arthrogryposis, defined as congenital joint contractures in 2 or more body areas, is a clinical sign rather than a specific disease diagnosis. To date, more than 400 different disorders have been described that present with arthrogryposis, and variants of more than 220 genes have been associated with these disorders; however, the underlying molecular etiology remains unknown in the considerable majority of these cases. METHODS: We performed whole exome sequencing (WES) of 52 patients with clinical presentation of arthrogryposis from 48 different families. RESULTS: Affected individuals from 17 families (35.4%) had variants in known arthrogryposis-associated genes, including homozygous variants of cholinergic γ nicotinic receptor (CHRNG, 6 subjects) and endothelin converting enzyme-like 1 (ECEL1, 4 subjects). Deleterious variants in candidate arthrogryposis-causing genes (fibrillin 3 [FBN3], myosin IXA [MYO9A], and pleckstrin and Sec7 domain containing 3 [PSD3]) were identified in 3 families (6.2%). Moreover, in 8 families with a homozygous mutation in an arthrogryposis-associated gene, we identified a second locus with either a homozygous or compound heterozygous variant in a candidate gene (myosin binding protein C, fast type [MYBPC2] and vacuolar protein sorting 8 [VPS8], 2 families, 4.2%) or in another disease-associated genes (6 families, 12.5%), indicating a potential mutational burden contributing to disease expression. CONCLUSION: In 58.3% of families, the arthrogryposis manifestation could be explained by a molecular diagnosis; however, the molecular etiology in subjects from 20 families remained unsolved by WES. Only 5 of these 20 unrelated subjects had a clinical presentation consistent with amyoplasia; a phenotype not thought to be of genetic origin. Our results indicate that increased use of genome-wide technologies will provide opportunities to better understand genetic models for diseases and molecular mechanisms of genetically heterogeneous disorders, such as arthrogryposis. FUNDING: This work was supported in part by US National Human Genome Research Institute (NHGRI)/National Heart, Lung, and Blood Institute (NHLBI) grant U54HG006542 to the Baylor-Hopkins Center for Mendelian Genomics, and US National Institute of Neurological Disorders and Stroke (NINDS) grant R01NS058529 to J.R. Lupski.

Mitochondrial complex I and III mRNA levels in bipolar disorder.

BACKGROUND: Studies that have focused on the mitochondrial electron transport chain indicate that bipolar disorder (BD) is associated with pathology in mitochondrial function. These pathological processes occur in the brain circuits that regulate affective functions, emotions, and motor behaviors. The present study aimed to determine the relationship between mitochondrial complex dysfunction and BD. METHODS: The BD group included 32 male patients diagnosed with first-episode manic BD. The control group included 35 sociodemographically matched healthy males. Messenger ribonucleic acid (mRNA) was isolated from peripheral blood samples obtained from the patients and control group, and the mRNA levels of the NDUFV1, NDUFV2, and NDUFS1 genes of mitochondrial complex I and the UQCR10 gene of mitochondrial complex III were investigated. RESULTS: Significant differences were identified in complex I gene mRNA levels between the BD group (n = 32) and the control group (n = 35) for the following genes: NDUFV1 (P = 0.01), NDUFV2 (P < 0.01), and NDUFS1 (P = 0.02). The UQCR10 gene (complex III) mRNA level did not differ between the groups (P = 0.1). The mRNA levels of the four genes studied were lower at the 3-month follow-up; however, these differences were not significant (P > 0.05). LIMITATIONS: All of the BD patients were in manic episodes; thus, we were unable to separately compare these levels with those during depressive and euthymic episodes. CONCLUSIONS: The mRNA levels of all of the genes representing the subunits of mitochondrial complex I (NDUFV1, NDUFV2, and NDUFS1) were significantly higher in the present study's BD patients during manic episodes than in the controls. With the data obtained from further research, biomarkers that could be used for the diagnosis and follow-up of neuropsychiatric disorders may be discovered.

The phenotypic and molecular genetic spectrum of Alström syndrome in 44 Turkish kindreds and a literature review of Alström syndrome in Turkey.

Alström syndrome (ALMS) is an autosomal recessive disease characterized by multiple organ involvement, including neurosensory vision and hearing loss, childhood obesity, diabetes mellitus, cardiomyopathy, hypogonadism, and pulmonary, hepatic, renal failure and systemic fibrosis. Alström Syndrome is caused by mutations in ALMS1, and ALMS1 protein is thought to have a role in microtubule organization, intraflagellar transport, endosome recycling and cell cycle regulation. Here, we report extensive phenotypic and genetic analysis of a large cohort of Turkish patients with ALMS. We evaluated 61 Turkish patients, including 11 previously reported, for both clinical spectrum and mutations in ALMS1. To reveal the molecular diagnosis of the patients, different approaches were used in combination, a cohort of patients were screened by the gene array to detect the common mutations in ALMS1 gene, then in patients having any of the common ALMS1 mutations were subjected to direct DNA sequencing or next-generation sequencing for the screening of mutations in all coding regions of the gene. In total, 20 distinct disease-causing nucleotide changes in ALMS1 have been identified, eight of which are novel, thereby increasing the reported ALMS1 mutations by 6% (8/120). Five disease-causing variants were identified in more than one kindred, but most of the alleles were unique to each single patient and identified only once (16/20). So far, 16 mutations identified were specific to the Turkish population, and four have also been reported in other ethnicities. In addition, 49 variants of uncertain pathogenicity were noted, and four of these were very rare and probably or likely deleterious according to in silico mutation prediction analyses. ALMS has a relatively high incidence in Turkey and the present study shows that the ALMS1 mutations are largely heterogeneous; thus, these data from a particular population may provide a unique source for the identification of additional mutations underlying Alström Syndrome and contribute to genotype-phenotype correlation studies.

Mitochondrial complex I and III gene mRNA levels in schizophrenia, and their relationship with clinical features.

BACKGROUND: The etiology of schizophrenia is not precisely known; however, mitochondrial function and cerebral energy metabolism abnormalities were determined to be possible factors associated with the etiology of schizophrenia. Impaired mitochondrial function negatively affects neuronal plasticity, and can cause cognitive deficits and behavioral abnormalities observed during the clinical course of schizophrenia. The present study aimed to investigate the relationship between the clinical features of schizophrenia, and mitochondrial complex activation, based on measurement of mRNA levels in the NDUFV1, NDUFV2, NDUFS1, and UQCR10 genes involved in the peripheral mitochondrial complex. METHODS: The study included 138 schizophrenia patients and 42 healthy controls. The schizophrenia group was divided into a chronic schizophrenia subgroup (n = 84) and a first-episode schizophrenia subgroup (n = 54). The symptoms profile and severity of disorder were evaluated using the Scale for the Assessment of Negative Symptoms (SANS), Scale for the Assessment of Positive Symptoms (SAPS), and Brief Psychiatric Rating Scale (BPRS). RESULTS: The level of mRNA expression of NDUFV1, NDUFV2, and NDUFS1 was significantly higher in the schizophrenia group than in the control group. The mRNA level of NDUFV2 was positively correlated with BPRS and SAPS scores in the first-episode schizophrenia subgroup. CONCLUSION: The findings showed that there was a positive correlation between gene mRNA levels and psychotic symptomatology, especially positive symptoms. Our results suggest that mRNA levels of the NDUFV1, NUDFV2, and NDUFS1 genes of complex I of the mitochondrial electron transport chain might become a possible peripheral marker for the diagnosis of schizophrenia.

The presence of MEFV gene mutations in patients with primary osteoarthritis who require surgery.

BACKGROUND/AIMS: Chronic arthritis of familial Mediterranean fever (FMF) involves weight-bearing joints and can occur in patients without a history of acute attack. Our aim was to investigate a possible causal relationship between FMF and osteoarthritis in a population in which FMF is quite common. METHODS: Patients with late stage primary osteoarthritis were enrolled, and five MEFV gene mutations were investigated. The frequency of MEFV gene mutations was compared among patients with osteoarthritis and a previous healthy group from our center. RESULTS: One hundred patients with primary osteoarthritis and 100 healthy controls were studied. The frequency of MEFV gene mutations was significantly lower in the osteoarthritis group (9% vs. 19%). M694V was the most frequent mutation (5%) in the osteoarthritis group, whereas in the control group, E148Q was the most common (16%). In subgroup analyses, the mutation frequency of patients with hip osteoarthritis was not different from that of patients with knee osteoarthritis and controls (7.1%, 9.7%, and 19%, respectively). There were no differences among the three groups with respect to MEFV gene mutations other than E148Q (8.1% vs. 3.6%). E148Q was significantly lower in the osteoarthritis group than in the controls (16% vs. 1%), although the mutations did not differ between patients with knee osteoarthritis and controls. CONCLUSIONS: In a population with a high prevalence of MEFV gene mutations, we did not find an increased mutation rate in patients with primary osteoarthritis. Furthermore, we found that some mutations were significantly less frequent in patients with osteoarthritis. Although the number of patients studied was insufficient to claim that E148Q gene mutation protects against osteoarthritis, the potential of this gene merits further investigation.

[The investigation of angiotensin converting enzyme I/D and plasminogen activator inhibitor-1 4G/5G polymorphisms in venous thromboembolism patients]. / Venöz tromboembolili hastalarda anjiyotensin dönüstürücü enzim I/D ve plazminojen aktivatör inhibitör-1 4G/5G gen polimorfizmlerinin arastirilmasi.

INTRODUCTION: Deep venous thrombosis and pulmonary embolism, known as venous thromboembolism and seen as a fairly common multifactorial diseases. Differ between populations due to genetic factors, several polymorphisms associated with venous thromboembolism was conducted. As a result of these studies the relationship between disease development and polymorphism is not clear yet. In this study we aimed to investigate the role of angiotensin converting enzyme insersion/deletion (ACE I/D) and plasminogen activator inhibitor-1 4G/5G (PAI-1 4G/5G) polymorphism in the development of disease. MATERIALS AND METHODS: In our study, DNA isolated from 80 venous thromboembolism patients and 79 control groups was used. While the classical polymerase chain reaction method used to investigate the ACE I/D polymorphism, the polymerase chain reaction based on allele-specific amplification was used for the detection of PAI-1 4G/5G polymorphism. RESULTS: As a result, there were no significant statistical differences for ACE I/D and PAI-1 4G/5G polymorphism among patient and control groups (p> 0.05). CONCLUSION: These findings revealed that there is no relationship between these polymorphisms and the development of venous thromboembolism, but large-scale studies are need to be done.

Gorlin-Chaudhry-Moss syndrome revisited: expanding the phenotype.

Gorlin-Chaudhry-Moss syndrome (OMIM 233500) is a rare congenital malformation syndrome with the cardinal manifestations of craniofacial dysostosis, hypertrichosis, underdeveloped genitalia, ocular, and dental anomalies. Since 1960, only six affected individuals have been reported. We report a 4-year and 6-month-old female patient with this phenotype and review the clinical presentation of all patients known so far. Previously unreported malformations of the extremities, larynx, and nose are also described, expanding the phenotype of this rare syndrome. Array-CGH analysis did not show pathological deletions or duplications.

Methylation of SOCS3 in Myeloproliferative Neoplasms and Secondary Erythrocytosis/Thrombocythemia.

OBJECTIVE: Myeloproliferative neoplasms (MPNs) like essential thrombocythemia (ET), polycythemia vera (PV), and primary myelofibrosis (PMF) are acquired clonal hematopoietic stem cell disorders and originate from a multipotent hematopoietic stem cell. The SOCS1 and SOCS3 genes are negative regulators of the JAK/STAT signal pathway. In this study we investigate the promoter methylation of these genes in the pathogenesis of MPNs and secondary erythrocytosis/thrombocythemia. MATERIALS AND METHODS: Promoter methylation of SOCS1 and SOCS3 genes was analyzed with methylation-specific PCR. PCR products were analyzed by agarose gel electrophoresis. RESULTS: No disease-specific CpG island methylation of SOCS1 was observed. Hypermethylation of the SOCS3 promoter was identified in 5 out of 19 (26.3%) PV cases, 2 out of 21 (9.5%) ET cases, 1 out of 5 (20%) PMF cases, and 9 out of 42 (21.4%) cases of secondary erythrocytosis/thrombocythemia. CONCLUSION: The results revealed that promoter methylation of the SOCS3 gene suggests a possible role for SOCS3 methylation in the pathogenesis of MPNs and secondary erythrocytosis/thrombocythemia. CONFLICT OF INTEREST: None declared.