H Syndrome: Three New Cases from Morocco.

A 19-year-old girl presented with symmetric and bilateral hyperpigmentation, an indurated lesion that initially appeared on the axillary fold at the age of 14, which then extended to the lower back, anterior aspect of both thighs, and popliteal fold. No hypertrichosis was observed (Figure 1).The patient was the youngest of the four children, born from the first-degree consanguineous marriage. She was born at full term and weighed 2,420 g at birth. No similar patient was present in the family. The patient experienced delayed motor acquisition and stature growth (3rd percentile) until the age of 4. Right hypoacusis was diagnosed at the age of 6. She developed hallux valgus, flexion contracture of the fin-gers and toes, barrel deformity of the anterior thorax, and recurrent fever. The laboratory tests, including fasting blood glucose, -triglycerides, C-reactive protein (CRP), and erythrocyte sedimentation rate (ESR) were normal. Her abdominal, pelvic, and transthoracic ultrasound scans were normal, with no hepatosplenomegaly, lymphadenopathy, or cardiac abnormalities. Histologic analysis demonstrated patchy acanthosis of the epidermis, with orthokeratotic hyperkeratosis. Keratinocyte hyperpigmentation and spongiosis at certain areas were observed with moder-ate inflammation because of the infiltration of lymphocytes, histiocytes, and plasma cells. Immunohistochemical analysis showed macrosialin (CD68+) and common gamma chain (γc) CD132. Germline mutations in the SLC29A3 gene were not analyzed. The patient was prescribed dermocorticoids with depigmentation therapy, which demonstrated moderate clinical evolution.

A novel start-loss mutation of the SLC29A3 gene in a consanguineous family with H syndrome: clinical characteristics, in silico analysis and literature review.

BACKGROUND: The SLC29A3 gene, which encodes a nucleoside transporter protein, is primarily located in intracellular membranes. The mutations in this gene can give rise to various clinical manifestations, including H syndrome, dysosteosclerosis, Faisalabad histiocytosis, and pigmented hypertrichosis with insulin-dependent diabetes. The aim of this study is to present two Iranian patients with H syndrome and to describe a novel start-loss mutation in SLC29A3 gene. METHODS: In this study, we employed whole-exome sequencing (WES) as a method to identify genetic variations that contribute to the development of H syndrome in a 16-year-old girl and her 8-year-old brother. These siblings were part of an Iranian family with consanguineous parents. To confirmed the pathogenicity of the identified variant, we utilized in-silico tools and cross-referenced various databases to confirm its novelty. Additionally, we conducted a co-segregation study and verified the presence of the variant in the parents of the affected patients through Sanger sequencing. RESULTS: In our study, we identified a novel start-loss mutation (c.2T > A, p.Met1Lys) in the SLC29A3 gene, which was found in both of two patients. Co-segregation analysis using Sanger sequencing confirmed that this variant was inherited from the parents. To evaluate the potential pathogenicity and novelty of this mutation, we consulted various databases. Additionally, we employed bioinformatics tools to predict the three-dimensional structure of the mutant SLC29A3 protein. These analyses were conducted with the aim of providing valuable insights into the functional implications of the identified mutation on the structure and function of the SLC29A3 protein. CONCLUSION: Our study contributes to the expanding body of evidence supporting the association between mutations in the SLC29A3 gene and H syndrome. The molecular analysis of diseases related to SLC29A3 is crucial in understanding the range of variability and raising awareness of H syndrome, with the ultimate goal of facilitating early diagnosis and appropriate treatment. The discovery of this novel biallelic variant in the probands further underscores the significance of utilizing genetic testing approaches, such as WES, as dependable diagnostic tools for individuals with this particular condition.

Equilibrative nucleoside transporter 3 supports microglial functions and protects against the progression of Huntington's disease in the mouse model.

Huntington's disease (HD) is a hereditary neurodegenerative disorder characterized by involuntary movements, cognitive deficits, and psychiatric symptoms. Currently, there is no cure, and only limited treatments are available to manage the symptoms and to slow down the disease's progression. The molecular and cellular mechanisms of HD's pathogenesis are complex, involving immune cell activation, altered protein turnover, and disturbance in brain energy homeostasis. Microglia have been known to play a dual role in HD, contributing to neurodegeneration through inflammation but also enacting neuroprotective effects by clearing mHTT aggregates. However, little is known about the contribution of microglial metabolism to HD progression. This study explores the impact of a microglial metabolite transporter, equilibrative nucleoside transporter 3 (ENT3), in HD. Known as a lysosomal membrane transporter protein, ENT3 is highly enriched in microglia, with its expression correlated with HD severity. Using the R6/2 ENT3-/- mouse model, we found that the deletion of ENT3 increases microglia numbers yet worsens HD progression, leading to mHTT accumulation, cell death, and disturbed energy metabolism. These results suggest that the delicate balance between microglial metabolism and function is crucial for maintaining brain homeostasis and that ENT3 has a protective role in ameliorating neurodegenerative processes.

Clinical Progression and Manifestations of H Syndrome: A Case Report of Failed Treatment Option.

BACKGROUND H syndrome is an autosomal recessive disorder of histiocytic proliferation with clinical spectrum of unique cutaneous and systemic manifestations. There is no consistent treatment for the disease, and all available options are based on case reports. Here, we present the chronological progression of a case of H syndrome with typical cutaneous manifestations that was misdiagnosed early as meningitis-induced sensorineural hearing loss and later as a non-defined autoimmune connective tissue disease. A new tried, although failed, treatment option is described as well. CASE REPORT A 31-year-old Saudi woman born of a consanguineous marriage presented to our dermatology clinic with symmetrical indurated hyperpigmented to violaceous plaques over the medial thighs, upper legs, lower back, volar wrists, and upper arms, associated with hypertrichosis. Hallux valgus of the big toes was clinically detected as well. She had a history of sensorineural deafness, diabetes mellitus, chronic anemia, and hypothyroidism. Genetic analysis of the patient showed a homozygous frameshift pathogenic variant of the SLC29A3 gene, c.243del p.(Lys81Asnfs*20). Systemic treatments in the form of methotrexate and imatinib had been tried; however, both failed to control her sclerotic cutaneous changes. CONCLUSIONS Knowing the early life presentation and the variable clinical symptoms of H syndrome is crucial in early intervention and further prevention of the non-reversible changes. Moreover, avoiding unnecessary immunosuppressive medication use is warranted in certain circumstances.

Combination of four features of SLC29A3 spectrum disorder in a child: A case report.

SLC29A3 spectrum disorder, also known as histiocytosis-lymphadenopathy plus syndrome (HLPS), presents a wide variety of multi-systemic manifestations that can be mistaken for other conditions. Herein, we report a 9-year-old girl who presented with a complex clinical presentation since birth, including chronic generalized lymphadenopathy in association with hepatosplenomegaly, short stature, flexion contractures, hearing loss, hyperpigmentation, and heart anomalies. She was ultimately diagnosed with the SLC29A3 spectrum disorder.

Identification of Coding Variants in 10q22.1 Associated with Vitiligo in the Chinese Han Population.

Objective: This study aims to identify causal variants associated with vitiligo in an expanded region of 10q22.1. Materials and Methods: We conducted a fine-scale deep analysis of the expanded 10q22.1 region using in a large genome-wide association studies dataset consisting of 1117 cases and 1701 controls through imputation. We selected five nominal coding single nucleotide polymorphisms (SNPs) located in SLC29A3 and CDH23 and genotyped them in an independent cohort of 2479 cases and 2451 controls in a Chinese Han population cohort using the Sequenom MassArray iPLEX1 system. Results: A missense SNP in SLC29A3, rs2252996, showed strong evidence of association with vitiligo (p = 1.34 × 10-8, odds ratio [OR] = 0.82). Three synonymous SNPs (rs1084004 in SLC29A3; rs12218559 and rs10999978 in CDH23) provided suggestive evidence of association for vitiligo (p = 1.69 × 10-6, OR = 0.84; p = 9.47 × 10-5, OR = 1.18; p = 6.90 × 10-4, OR = 1.16, respectively). Stepwise conditional analyses identified two significant independent disease-associated signals from the four SNPs (both p < 0.05; both D' = 0.03; and r2 = 0.00). Conclusion: The study identifies four genetic coding variants in SLC29A3 and CDH23 on 10q22.1 that may contribute to vitiligo susceptibility with one missense variant affecting disease subphenotypes. The presence of multiple genetic variants underscores their significant role in the genetic pathogenesis of the disease.

Cases with the H syndrome presenting with skin and bone findings.

BACKGROUND: The H syndrome is an autosomal recessive disease characterized by hyperpigmentation, hypertrichosis and sensorineural hearing loss. METHODS: A mutation in the coding of the human equilibrative nucleoside transporter 3 (hENT3) within the SLC29A3 gene on chromosome 10q22 leads to the manifestation of this disease. In this report, we present two cases of H syndrome. RESULTS: The first patient exhibits hyperpigmentation, hypogonadism, Type 1 diabetes mellitus, arthritis and osteoporosis. The second patient experiences hyperpigmentation, hypertrichosis, osteopenia and hypogonadism. CONCLUSION: Our objective is to broaden the clinical spectrum of H syndrome, highlighting the involvement of arthritis, hyperinflammation and low bone mineral density in individuals with this disorder.

Blood DNA methylation signature of diet quality and association with cardiometabolic traits.

AIMS: Diet quality might influence cardiometabolic health through epigenetic changes, but this has been little investigated in adults. Our aims were to identify cytosine-phosphate-guanine (CpG) dinucleotides associated with diet quality by conducting an epigenome-wide association study (EWAS) based on blood DNA methylation (DNAm) and to assess how diet-related CpGs associate with inherited susceptibility to cardiometabolic traits: body mass index (BMI), systolic blood pressure (SBP), triglycerides, type 2 diabetes (T2D), and coronary heart disease (CHD). METHODS AND RESULTS: Meta-EWAS including 5274 participants in four cohorts from Spain, the USA, and the UK. We derived three dietary scores (exposures) to measure adherence to a Mediterranean diet, to a healthy plant-based diet, and to the Dietary Approaches to Stop Hypertension. Blood DNAm (outcome) was assessed with the Infinium arrays Human Methylation 450K BeadChip and MethylationEPIC BeadChip. For each diet score, we performed linear EWAS adjusted for age, sex, blood cells, smoking and technical variables, and BMI in a second set of models. We also conducted Mendelian randomization analyses to assess the potential causal relationship between diet-related CpGs and cardiometabolic traits. We found 18 differentially methylated CpGs associated with dietary scores (P < 1.08 × 10-7; Bonferroni correction), of which 12 were previously associated with cardiometabolic traits. Enrichment analysis revealed overrepresentation of diet-associated genes in pathways involved in inflammation and cardiovascular disease. Mendelian randomization analyses suggested that genetically determined methylation levels corresponding to lower diet quality at cg02079413 (SNORA54), cg02107842 (MAST4), and cg23761815 (SLC29A3) were causally associated with higher BMI and at cg05399785 (WDR8) with greater SBP, and methylation levels associated with higher diet quality at cg00711496 (PRMT1) with lower BMI, T2D risk, and CHD risk and at cg0557921 (AHRR) with lower CHD risk. CONCLUSION: Diet quality in adults was related to differential methylation in blood at 18 CpGs, some of which related to cardiometabolic health.

We conducted a study to investigate the connection between diet quality, epigenetic changes, and cardiovascular health in adults. The study included 5274 participants from Spain, the USA, and the UK, combining data from four different cohorts. We assessed adherence to different healthy diets: Mediterranean style diet, plant-based diet, and Dietary Approaches to Stop Hypertension diet. We used advanced technology to analyse blood DNA methylation, which refers to chemical modifications in the DNA that can affect gene activity.We discovered 18 CpGs that showed differential methylation patterns related to the dietary scores. Importantly, 12 of these CpGs had previously been associated with cardiovascular disease or risk factors, suggesting a potential link between diet, epigenetic changes, and heart health. Some of the diet-related CpGs mapped to genes involved in pathways associated with cardiovascular disease. Moreover, using a method called Mendelian randomization, we found that several CpGs may have a causal association with body mass index, systolic blood pressure, and risk of type 2 diabetes and coronary heart disease.

Paediatric diabetes subtypes in a consanguineous population: a single-centre cohort study from Kurdistan, Iraq.

AIMS/HYPOTHESIS: Monogenic diabetes is estimated to account for 1-6% of paediatric diabetes cases in primarily non-consanguineous populations, while the incidence and genetic spectrum in consanguineous regions are insufficiently defined. In this single-centre study we aimed to evaluate diabetes subtypes, obtain the consanguinity rate and study the genetic background of individuals with syndromic and neonatal diabetes in a population with a high rate of consanguinity. METHODS: Data collection was carried out cross-sectionally in November 2021 at the paediatric diabetic clinic, Dr Jamal Ahmad Rashed Hospital, in Sulaimani, Kurdistan, Iraq. At the time of data collection, 754 individuals with diabetes (381 boys) aged up to 16 years were registered. Relevant participant data was obtained from patient files. Consanguinity status was known in 735 (97.5%) participants. Furthermore, 12 families of children with neonatal diabetes and seven families of children with syndromic diabetes consented to genetic testing by next-generation sequencing. Prioritised variants were evaluated using the American College of Medical Genetics and Genomics guidelines and confirmed by Sanger sequencing. RESULTS: A total of 269 of 735 participants (36.5%) with known consanguinity status were offspring of consanguineous families. An overwhelming majority of participants (714/754, 94.7%) had clinically defined type 1 diabetes (35% of them were born to consanguineous parents), whereas only eight (1.1%) had type 2 diabetes (38% consanguineous). Fourteen (1.9%) had neonatal diabetes (50% consanguineous), seven (0.9%) had syndromic diabetes (100% consanguineous) and 11 (1.5%) had clinically defined MODY (18% consanguineous). We found that consanguinity was significantly associated with syndromic diabetes (p=0.0023) but not with any other diabetes subtype. The genetic cause was elucidated in ten of 12 participants with neonatal diabetes who consented to genetic testing (homozygous variants in GLIS3 [sibling pair], PTF1A and ZNF808 and heterozygous variants in ABCC8 and INS) and four of seven participants with syndromic diabetes (homozygous variants in INSR, SLC29A3 and WFS1 [sibling pair]). In addition, a participant referred as syndromic diabetes was diagnosed with mucolipidosis gamma and probably has type 2 diabetes. CONCLUSIONS/INTERPRETATION: This unique single-centre study confirms that, even in a highly consanguineous population, clinically defined type 1 diabetes is the prevailing paediatric diabetes subtype. Furthermore, a pathogenic cause of monogenic diabetes was identified in 83% of tested participants with neonatal diabetes and 57% of participants with syndromic diabetes, with most variants being homozygous. Causative genes in our consanguineous participants were markedly different from genes reported from non-consanguineous populations and also from those reported in other consanguineous populations. To correctly diagnose syndromic diabetes in consanguineous populations, it may be necessary to re-evaluate diagnostic criteria and include additional phenotypic features such as short stature and hepatosplenomegaly.

Equilibrative nucleotide transporter ENT3 (SLC29A3): A unique transporter for inherited disorders and cancers.

As a crucial gene associated with diseases, the SLC29A3 gene encodes the equilibrative nucleoside transporter 3 (ENT3). ENT3 plays an essential regulatory role in transporting intracellular hydrophilic nucleosides, nucleotides, hydrophilic anticancer and antiviral nucleoside drugs, energy metabolism, subcellular localization, protein stability, and signal transduction. The mutation and inactivation of SLC29A3 are intimately linked to the occurrence, development, and prognosis of various human tumors. Moreover, many hereditary human diseases, such as H syndrome, pigmentary hypertrichosis and non-autoimmune insulin-dependent diabetes mellitus (PHID) syndrome, Faisalabad histiocytosis (FHC), are related to SLC29A3 mutations. This review explores the mechanisms of SLC29A3 mutations and expression alterations in inherited disorders and cancers. Additionally, we compile studies on the inhibition of ENT3, which may serve as an effective strategy to potentiate the anticancer activity of chemotherapy. Thus, the synopsis of genetics, permeant function and drug therapy of ENT3 provides a new theoretical and empirical foundation for the diagnosis, prognosis of evaluation and treatment of various related diseases.

Hyperglycemia with hypogonadism and growth hormone deficiency in a 17-year-old male with H syndrome: the first case report from Syria.

BACKGROUND: The nucleoside transport capabilities of the human equilibrative nucleoside transporter-3 (hENT3) are disrupted by mutations in SLC29A3 (10q22.2), which are genes for the nucleoside transporter and are the cause of the unusual autosomal recessive disease known as H syndrome. As a result, histiocytic cells invade a number of organs. CASE PRESENTATION: A 17-year-old Syrian male was admitted to the internal medicine department with a one-month history of polyuria, polydipsia, general weakness, and pallor. He had a history of progressive bilateral sensorineural hearing loss and failure to gain weight for three years. Physical examination revealed various abnormalities, including scrotal mass, small penis and testicles, absence of pubic and axillary hair, joint abnormalities, short stature, hallux valgus, fibrous protrusion near the navel, and hyperpigmented non-itchy painful skin plaques. Clinical signs along with laboratory test results confirmed hyperglycemia, primary hypogonadism, osteopenia, and growth hormone deficiency. After a review of the relevant medical literature, this patient's presentation of hyperglycemia with hypogonadism, hyperpigmentation, hallux valgus, hearing loss, hematological abnormalities, and short stature suggested the diagnosis of H syndrome. The patient received treatment with insulin and testosterone, leading to a significant improvement in his presenting symptoms. CONCLUSIONS: H syndrome is a very rare condition, and the fact that the first case has only recently been reported in Syria serves to emphasize how rare it is. H Syndrome should be suspected if a patient has short stature with signs of hyperglycemia and other endocrine and cutaneous abnormalities. We are reporting this case to increase physicians' awareness of this exceedingly rare and unique syndrome.

Transcriptome screening identifies TIPARP as an antiviral host factor against the Getah virus.

IMPORTANCE: Alphaviruses threaten public health continuously, and Getah virus (GETV) is a re-emerging alphavirus that can potentially infect humans. Approved antiviral drugs and vaccines against alphaviruses are few available, but several host antiviral factors have been reported. Here, we used GETV as a model of alphaviruses to screen for additional host factors. Tetrachlorodibenzo-p-dioxin-inducible poly(ADP ribose) polymerase was identified to inhibit GETV replication by inducing ubiquitination of the glycoprotein E2, causing its degradation by recruiting the E3 ubiquitin ligase membrane-associated RING-CH8 (MARCH8). Using GETV as a model virus, focusing on the relationship between viral structural proteins and host factors to screen antiviral host factors provides new insights for antiviral studies on alphaviruses.

Loss of function of ENT3 drives histiocytosis and inflammation through TLR-MAPK signaling.

Histiocytoses are inflammatory myeloid neoplasms often driven by somatic activating mutations in mitogen-activated protein kinase (MAPK) cascade genes. H syndrome is an inflammatory genetic disorder caused by germ line loss-of-function mutations in SLC29A3, encoding the lysosomal equilibrative nucleoside transporter 3 (ENT3). Patients with H syndrome are predisposed to develop histiocytosis, yet the mechanism is unclear. Here, through phenotypic, molecular, and functional analysis of primary cells from a cohort of patients with H syndrome, we reveal the molecular pathway leading to histiocytosis and inflammation in this genetic disorder. We show that loss of function of ENT3 activates nucleoside-sensing toll-like receptors (TLR) and downstream MAPK signaling, inducing cytokine secretion and inflammation. Importantly, MEK inhibitor therapy led to resolution of histiocytosis and inflammation in a patient with H syndrome. These results demonstrate a yet-unrecognized link between a defect in a lysosomal transporter and pathological activation of MAPK signaling, establishing a novel pathway leading to histiocytosis and inflammation.

H syndrome treated with Tocilizumab: two case reports and literature review.

H syndrome is a rare autosomal recessive genetic disorder characterized by the following clinical features: cutaneous hyperpigmentation, hypertrichosis, hepatosplenomegaly, heart anomalies, hearing loss, hypogonadism, short stature, hallux valgus, hyperglycemia, fixed flexion contractures of the toe joints, and the proximal interphalangeal joints. In rare cases, autoinflammatory and lymphoproliferative manifestations have also been reported. This disorder is due to loss-of-function mutations in SLC29A3 gene, which encode the equilibrative nucleoside transporter ENT3. This deficiency leads to abnormal function and proliferation of histiocytes. H syndrome is part of the R-group of histiocytosis. We report two different cases, one was diagnosed in adulthood and the other in childhood. The first case reported is a 37-year-old woman suffering from H syndrome with an autoinflammatory systemic disease that begins in adulthood (fever and diffuse organ's infiltration) and with cutaneous, articular, auditory, and endocrinological manifestations since childhood. The second case reported is a 2-year-old girl with autoinflammatory, endocrine, and cutaneous symptoms (fever, lymphadenopathy, organomegaly, growth delay, and cutaneous hyperpigmentation). Homozygous mutations in SLC29A3 confirmed the diagnosis of H syndrome in both cases. Each patient was treated with Tocilizumab with a significant improvement for lymphoproliferative, autoinflammatory, and cutaneous manifestations. Both cases were reported to show the multiple characteristics of this rare syndrome, which can be diagnosed either in childhood or in adulthood. In addition, an overview of the literature suggested Tocilizumab efficiency.

Structural basis of the substrate recognition and inhibition mechanism of Plasmodium falciparum nucleoside transporter PfENT1.

By lacking de novo purine biosynthesis enzymes, Plasmodium falciparum requires purine nucleoside uptake from host cells. The indispensable nucleoside transporter ENT1 of P. falciparum facilitates nucleoside uptake in the asexual blood stage. Specific inhibitors of PfENT1 prevent the proliferation of P. falciparum at submicromolar concentrations. However, the substrate recognition and inhibitory mechanism of PfENT1 are still elusive. Here, we report cryo-EM structures of PfENT1 in apo, inosine-bound, and inhibitor-bound states. Together with in vitro binding and uptake assays, we identify that inosine is the primary substrate of PfENT1 and that the inosine-binding site is located in the central cavity of PfENT1. The endofacial inhibitor GSK4 occupies the orthosteric site of PfENT1 and explores the allosteric site to block the conformational change of PfENT1. Furthermore, we propose a general "rocker switch" alternating access cycle for ENT transporters. Understanding the substrate recognition and inhibitory mechanisms of PfENT1 will greatly facilitate future efforts in the rational design of antimalarial drugs.

Neuronal activity-induced, equilibrative nucleoside transporter-dependent, somatodendritic adenosine release revealed by a GRAB sensor.

The purinergic signaling molecule adenosine (Ado) modulates many physiological and pathological functions in the brain. However, the exact source of extracellular Ado remains controversial. Here, utilizing a newly optimized genetically encoded GPCR-Activation-Based Ado fluorescent sensor (GRABAdo), we discovered that the neuronal activity-induced extracellular Ado elevation is due to direct Ado release from somatodendritic compartments of neurons, rather than from the axonal terminals, in the hippocampus. Pharmacological and genetic manipulations reveal that the Ado release depends on equilibrative nucleoside transporters but not the conventional vesicular release mechanisms. Compared with the fast-vesicular glutamate release, the Ado release is slow (~40 s) and requires calcium influx through L-type calcium channels. Thus, this study reveals an activity-dependent second-to-minute local Ado release from the somatodendritic compartments of neurons, potentially serving modulatory functions as a retrograde signal.

IFN-stimulated metabolite transporter ENT3 facilitates viral genome release.

An increasing amount of evidence emphasizes the role of metabolic reprogramming in immune cells to fight infections. However, little is known about the regulation of metabolite transporters that facilitate and support metabolic demands. In this study, we found that the expression of equilibrative nucleoside transporter 3 (ENT3, encoded by solute carrier family 29 member 3, Slc29a3) is part of the innate immune response, which is rapidly upregulated upon pathogen invasion. The transcription of Slc29a3 is directly regulated by type I interferon-induced signaling, demonstrating that this metabolite transporter is an interferon-stimulated gene (ISG). Suprisingly, we unveil that several viruses, including SARS-CoV-2, require ENT3 to facilitate their entry into the cytoplasm. The removal or suppression of Slc29a3 expression is sufficient to significantly decrease viral replication in vitro and in vivo. Our study reveals that ENT3 is a pro-viral ISG co-opted by some viruses to gain a survival advantage.

Renal Involvement in H Syndrome, A Rare Cause of Diabetes Mellitus: Case Report.

BACKGROUND: H syndrome is a rare genodermatosis deriving from a mutation in the SLC29A3 gene and affecting numerous systems, particularly the skin. The syndrome exhibits different clinical characteristics involving several systems, most beginning with the letter "H." The most common clinical findings are cutaneous hyperpigmentation, flexion contracture in the fingers, hearing loss, short stature, insulin-dependent diabetes mellitus, heart anomalies, hepatosplenomegaly, and hypogonadism. Fewer than 150 cases have been reported so far and vast majority of them consisted with patients with Arab ethnicity. CASE PRESENTATION: We describe a patient presenting with short stature, developing diabetes mellitus at follow-ups, with homozygous deletion determined in exon 3 of the SLC29A3 gene, and diagnosed with H syndrome, reported due to the presence and rarity of renal involvement (hematuria and proteinuria). CONCLUSION: In conclusion, despite its rarity, endocrinologists, rheumatologists/nephrologists, and dermatologists need to be aware of H syndrome as a pleiotropic syndrome. H syndrome should be considered in the differential diagnosis of patients with cutaneous hyperpigmentation (particularly in the bilateral thigh and calf region) together with proteinuria/hematuria. In addition, periodic urine analysis should be performed in patients with H syndrome.