Mutation analysis and clinical characterization of Iranian patients with mucopolysaccharidosis type I.

BACKGROUND: Mucopolysaccharidosis type I (MPSI) is a rare autosomal recessive disorder caused by a deficiency of α-l-iduronidase (IDUA) encoded by the IDUA gene. We examined the mutation spectrum of the IDUA gene to explain the clinical, biochemical, and molecular features in 21 Iranian patients with MPSI. METHODS: Sanger sequencing was used to measure the IDUA gene sequence in the coding region and exon-intron boundaries. We recorded the clinical findings of studied patients at the first diagnosis of disease and then during the treatment and follow-up. RESULTS: Five different missense disease-causing mutations were determined in our patient groups, indicating 90.48% of detection rate. The most widespread mutation was the p.Y109H, occurring in 15.625% of all alleles, which was reported for the first time in our study. Other frequent mutations were as follows: p.Ser157Pro (12.5%), p.Gly84Arg (12.5%), p.Asp257His (9.375%), and p.Asp301Glu (9.375%). Three ones of them were new missense mutations: p.Ser157Pro, p.Asp257His, and p.Asp301Glu. DISCUSSION: The results of this study explain the different spectrum of IDUA gene mutations in our patients with MPSI. We introduced here 32 different variants including four new variants: p.Y109H (15.625%), p.S157P (12.5%), p.D257H (9.375%), and p.D301E (9.375%). In this series, there was no relationship between the happening of clinical features and genotype variations and biochemical findings.

Mutations in HNF1A Gene are not a Common Cause of Familial Young-Onset Diabetes in Iran.

Mutations in hepatocyte nuclear factor-1 alpha (HNF1A) as a homeodomain transcription factor which regulates variety of genes, are the most common cause of maturity-onset diabetes of the young (MODY). Detection of HNF1A mutations not only classifies the subtype, but also predicts the likely clinical course and may alters the method of treatment from insulin to the oral sulphonylureas, which is shown to improve glycemic control. The coding and promoter regions of HNF1A gene were screened for mutations in 34 unrelated Iranian MODY patients. We identified one novel missense mutation (C49G) and two novel polymorphisms and 8 recently identified SNPs in the HNF1A gene. It is possible that in Iran, other yet to be identified genes are responsible for the familial young onset diabetes. Hence, there is a need for more extensive genetic analyses in Iranian patients with familial young onset diabetes.

Congenital Adrenal Hyperplasia and Schmid Metaphyseal Chondrodysplasia in a Child.

Congenital adrenal hyperplasia (CAH) is a group of hereditary diseases, which are autosomal recessive. CAH occurs due to defect in one of the cortisol coding genes and often clinically presents itself with signs of androgen overproduction. In this article, we report a case of CAH and Schmid metaphyseal dysplasia. Our literature review indicated that this report is the first attempt on CYP11B1 and Schmid dysplasia in a child. The specific diagnosis of 11-ß-hydroxylase deficiency can be determined using high basal levels of deoxycorticosterone and/or 11-deoxycortisol serums.

Hearing disorders in Turner's syndrome: a survey from Iran.

Turner syndrome (TS) is one of the most frequently encountered sex-linked chromosomal abnormalities, occurring in one per 2,000 female births. These patients present with short stature and failure to begin puberty. In this syndrome, there are multiple organ abnormalities, including auditory disorders. TS patients were referred to the ENT clinic by a pediatric endocrinologist. A questionnaire was filled out and the patients went through a complete otologic examination. They were then referred to the audiology clinic to undergo audiologic test battery plus high-frequency pure tone audiometry. From a total of 48 ears examined, 11 (22.9 %) had a normal audiometry. Mid-frequency sensorineural hearing loss (SNHL), high-frequency SNHL, combined and mixed hearing loss were diagnosed in 6 (12/5 %), 20 (41/7 %), 6 (12/5 %) and 1 (2/1 %) ear, respectively. Tympanogram results showed normal compliance (A, As, Ad) in the majority of cases. B and C patterns were found in a few cases. Speech discrimination score was normal in all patients whereas speech reception threshold was normal in 92 % of the ears. Audiometry abnormality especially SNHL is common in TS patients, with the high-frequency pattern being the most frequent.

Determination of Biological Variance and Validation of a Fluorometric Assay for Measurement of α-l-Iduronidase Activity in Dried Blood Spots Samples: The First Experience in Iran.

Methods for assaying lysosomal diseases in dried blood samples are very useful today due to its several advantages related to the stability of samples, its transportation, handled and analysis, and its potential use for newborn screening compared to traditional methods in leucocytes samples. For this reason, it is important to validate these assays before being used in routine laboratory. Because of different in biological markers based on ethnicity, we aimed this study to validation a DBS-based fluorometric assay for measurement of α-l-Iduronidase activity for diagnosis of MPS I patients in Iran. DBS samples were collected from 15 MPS I patients and 60 healthy age matched subjects. Diagnostic value, biological variance and α-l-Iduronidase activity were determined. DBS α-l-Iduronidase activity was significantly higher in male subjects than in female group. Using a cut-off level of 1.08 µmol/spot 20 h, sensitivity and specificity were 100 and 98 %. The linearity of test was proved and we showed that within-run and between run precision were 5.6 and 14.66 %. Measurement of α-l-Iduronidase activity in DBS samples is an accurate test for diagnosis of MPS I and because of its rapid shipping and simplicity to keeping, DBS-based enzyme activity could be considered as a useful diagnostic tool in this disease.

Comparison of Novel Coronary Artery Disease Risk Factors between Obese and Normal Adolescent.

BACKGROUND: Coronary artery disease is considered as the most common cause of death in all societies including Iran. This study seeks to compare the new risk factors of coronary-artery diseases in obese adolescents and control group. METHODS: In this cross-sectional study, amongst the obese adolescents registered in the nutrition clinic of Ghaem Hospital, 80 individuals were selected. As the control group, additional 80 adolescent students having the same gender and age as the obese group, but with normal weight were selected. These two groups were selected randomly and their serum level of vitamin D, anti-heat shock protein27 (HSP27), balance of oxidants and antioxidants, and homocysteine were determined and compared. RESULTS: In this study, 42 (53.2%) and 37 (46.8%) of the obese and normal weight groups were male, respectively. The mean value of triglyceride, cholesterol, and LDL in the obese group was higher than the normal group, but the mean value for HDL, vitamin D, homocysteine, PAB (Preoxidant and Antioxidants Balance), and anti-HSP27 was not significantly different between the groups. In the base of homocysteine >15 µmol/l, 26.6% of the obese group had hyperhomocysteinemia, therefore homocysteine may be a new risk factor for coronary artery disease in obese adolescents (χ(2)=4.072; P value=0.091). CONCLUSION: The findings of this study showed that despite the presence of obesity in adolescence and adolescents, new risk factors are not present among them more than the control group. This was in contrast to what was seen in adults.

Genetic variant profiling of neonatal diabetes mellitus in Iranian patients: Unveiling 58 distinct variants in 14 genes.

INTRODUCTION: Neonatal diabetes mellitus (NDM) is a rare non-immunological monogenic disorder characterized by hyperglycemic conditions primarily occurring within the first 6 months of life. The majority of cases are attributed to pathogenic variants in genes affecting beta-cell survival, insulin regulation, and secretion. This study aims to investigate the genetic landscape of NDM in Iran. METHODS: We recruited a total of 135 patients who were initially diagnosed with diabetes at <12 months of age in Iran and referred to pediatric endocrinology clinics across the country. These patients underwent genetic diagnostic tests conducted by the Exeter Molecular Genetics Laboratory in the UK. The pathogenic variants identified were sorted and described based on type, pathogenicity (according to ACMG/AMP criteria), novelty, and the affected protein domain. RESULTS: Genetic defects were identified in 93 probands, presenting various pathogenic abnormalities associated with NDM and its associated syndromes. 76% of the patients were born as a result of consanguineous marriage, and a familial history of diabetes was found in 43% of the cases. A total of 58 distinct variants in 14 different genes were discovered, including 20 variants reported for the first time. Causative variants were most frequently identified in EIF2AK3, KCNJ11, and ABCC8, respectively. Notably, EIF2AK3 and ABCC8 exhibited the highest number of novel variants. DISCUSSION: These findings provide valuable insights into the genetic landscape of NDM in the Iranian population and contribute to the knowledge of novel pathogenic variants within known causative genes.

Effects of Trehalose Administration in Patients with Mucopolysaccharidosis Type III.

BACKGROUND AND AIM: Mucopolysaccharidosis type III (MPS III) is a rare autosomal recessive lysosomal storage disease (LSD) caused by a deficiency of lysosomal enzymes required for the catabolism of glycosaminoglycans (GAGs), mainly in the central nervous system. Trehalose has been proposed as a potential therapeutic agent to attenuate neuropathology in MPS III. We conducted a single-arm, open-label study to evaluate the efficacy of trehalose treatment in patients with MPS IIIA and MPS IIIB. METHODS: Five patients with MPS III were enrolled. Trehalose was administrated intravenously (15 g/week) for 12 weeks. Health-related quality of life and cognitive function, serum biomarkers, liver, spleen, and lung imaging were assessed to evaluate trehalose efficacy at baseline and trial end (week 12). RESULTS: TNO-AZL Preschool children Quality of Life (TAPQOL) scores increased in all patients, and the mean scores for quality of life were increased after the intervention. Serum GAG levels were reduced in all treated patients (however, the differences were not statistically significant). Alanine aminotransferase (ALT) levels were reduced in all patients post-treatment (p=0.0039). The mean levels of aspartate transaminase (AST) were also decreased after 12 weeks of treatment with Trehalose. Decreased serum pro-oxidant-antioxidant balance and increased GPX activity were observed at the end of the study. Decreases in mean splenic length were observed, whereas the liver volume did not change. CONCLUSION: Improvements in health-related quality of life and serum biomarkers (GAGs, liver aminotransferase levels, antioxidant status), as well as liver and spleen size, were found following 3 months of trehalose administration in patients with MPS IIIA and MPS IIIB.

Meier-Gorlin syndrome with prenatal ultrasound findings and successful growth hormone therapy: Six years follow-up of a rare case.

Meire-Gorlin syndrome (MGS) is a rare autosomal recessive disorder characterized by a triad of short stature, microtia, and absent or hypoplastic patella. We report a 5-year-old male affected with the subtype MGS1, secondary to c.c2292t mutation of ORC1 gene. Our patient's features included a triangular face, micrognathia, and delayed motor development. To the edge of our knowledge, this is the first diagnosed Iranian MGS patient and sixth case in the middle east. MGS1 subtype has never shown improvement to growth hormone therapy, therefore underlying molecular defect was suggested to be responsible for patients' short stature rather than growth hormone deficiency. However, our patients' growth velocity was improved by growth hormone. We recommend more studies to specify the role of ORC1 gene in this syndrome. In addition, this case report describes the prenatal investigations and sonographic examinations of MGS1 for the first time.

Impact of Intravenous Trehalose Administration in Patients with Niemann-Pick Disease Types A and B.

BACKGROUND AND AIMS: Niemann-Pick disease (NPD) types A (NPA) and B (NPB) are caused by deficiency of the acid sphingomyelinase enzyme, which is encoded by the SMPD1 gene, resulting in progressive pathogenic accumulation of lipids in tissues. Trehalose has been suggested as an autophagy inducer with therapeutic neuroprotective effects. We performed a single-arm, open-label pilot study to assess the potential efficacy of trehalose treatment in patients with NPA and NPB patients. METHODS: Five patients with NPD type A and B were enrolled in an open-label, single-arm clinical trial. Trehalose was administrated intravenously (IV) (15 g/week) for three months. The efficacy of trehalose in the management of clinical symptoms was evaluated in patients by assessing the quality of life, serum biomarkers, and high-resolution computed tomography (HRCT) of the lungs at the baseline and end of the interventional trial (day 0 and week 12). RESULTS: The mean of TNO-AZL Preschool children Quality of Life (TAPQOL) scores increased in all patients after intervention at W12 compared to the baseline W0, although the difference was not statistically significant. The serum levels of lyso-SM-509 and lyso-SM were decreased in three and four patients out of five, respectively, compared with baseline. Elevated ALT and AST levels were decreased in all patients after 12 weeks of treatment; however, changes were not statistically significant. Pro-oxidant antioxidant balance (PAB) was also decreased and glutathione peroxidase (GPX) activity was increased in serum of patients at the end of the study. Imaging studies of spleen and lung HRCT showed improvement of symptoms in two patients. CONCLUSIONS: Positive trends in health-related quality of life (HRQoL), serum biomarkers, and organomegaly were observed after 3 months of treatment with trehalose in patients with NPA and NPB. Although not statistically significant, due to the small number of patients enrolled, these results are encouraging and should be further explored.

Investigating Genetic Mutations in a Large Cohort of Iranian Patients with Congenital Hyperinsulinism

Objective: Congenital hyperinsulinism (CHI) is the most frequent cause of severe and persistent hypoglycaemia from birth. Understanding the pathophysiology and genetic defects behind hyperinsulinism and its complications provides clues to timely diagnosis and management. The aim of this study was to evaluate the underlying genetic aetiology of a specific Iranian pediatric cohort with CHI. Methods: A total of 44 unrelated children, 20 girls and 24 boys, with an initial diagnosis or history of CHI from all regions of Iran were recruited between 2016 and 2019. Targeted next generation sequencing (tNGS) was performed for the genes found in about half of CHI patients. Results: Mutations were identified in 24 cases (55%). Patients with a confirmed genetic cause were mainly diagnosed below age of one year old (p=0.01), had fewer other syndromic features, excluding seizure, (p=0.03), were less diazoxide responsive (p=0.04) and were more diazoxide unresponsive leading to pancreatectomy (p=0.007) compared to those with no identified mutations. Among 24 patients with identified genetic mutations, 17 (71%) had a mutation in ABCC8, 3 (12%) in KCNJ11, 3 (12%) in HADH, and 1 patient had a mutation in KMT2D. These included five novel mutations in ABCC8, KCNJ11, and KMT2D. Conclusion: This is the biggest genetic study of CHI in Iran. A high frequency of recessive forms of CHI, especially HADH mutations, in our study could be due to a high rate of consanguineous marriage. We recommend tNGS to screen for all the CHI genes.

Bioavailability of rectal acetaminophen in children following anorectal surgery.

BACKGROUND: Acetaminophen is widely used as an analgesic and antipyretic agent in pediatrics. Although bioavailability of rectal acetaminophen is unpredictable, rectal route is a usual and acceptable method of prescription. Major anorectal surgery may alter the normal structure of the surgical site, especially the vascular elements and the normal connections between port and systemic vessels. As a result the pharmacokinetics of rectal medications might also be altered. Based on this hypothesis, we decided to study acetaminophen plasma concentration among children who underwent these types of surgeries to determine the pharmacokinetic of absorption, plasma concentration, safety, and efficacy of rectal acetaminophen. MATERIALS AND METHODS: The study included 20 cases with previous history of pull-through procedure owing to Hirschsprung's disease (HD), 20 cases with imperforate anus (IA) reconstructive surgeries who were admitted for colostomy closure, and 20 otherwise healthy cases of inguinal herniotomy. Venus blood sampling was done 4, 8 and 12 hrs after a single loading dose of rectal acetaminophen (40 mg/kg), and plasma acetaminophen concentration was compared between groups. RESULTS: Mean serum acetaminophen levels of the HD group were significantly higher than those of the herniotomy group (36.3 ±â€¯6.79, 27.4 ±â€¯8.42, 16.8 ±â€¯7.62 versus 25.9 ±â€¯9.12, 16.7 ±â€¯6.74, 8.1 ±â€¯5.79 (µg/ml) at 4, 8 and 12 hrs after drug administration and P < 0.05). The IA group had higher concentrations of plasma acetaminophen compared to the herniotomy group; however, the p values were not statistically significant. (31.4 ±â€¯10.39, 21.5 ±â€¯9.12, 13.3 ±â€¯6.79 versus 25.9 ±â€¯9.12, 16.7 ±â€¯6.74, 8.1 ±â€¯5.79 (µg/ml) at 4, 8 and 12 hrs after drug administration). Serum concentrations of acetaminophen in IA and HD patients were above the therapeutic range four hours after administering the loading dose (31.4 ±â€¯10.39 and 36.3 ±â€¯6.79 versus 5-20 µg/ml). CONCLUSION: Bioavailability of rectal acetaminophen might get altered after major anorectal surgery in children. Rectal acetaminophen should be administered with special caution among infants with history of anorectal operations. Repeated dose of rectal acetaminophen may cause the drug blood concentration to reach toxic levels in these patients. TYPE OF STUDY: Prospective comparative study. LEVEL OF EVIDENCE: Level II.

Genotyping of ABCC8, KCNJ11, and HADH in Iranian Infants with Congenital Hyperinsulinism.

BACKGROUND: Congenital hyperinsulinism (CHI) is a heterogeneous disease with various underlying genetic causes. Among different genes considered effective in the development of CHI, ABCC8, KCNJ11, and HADH genes are among the important genes, especially in a population with a considerable rate of consanguineous marriage. Mutational analysis of these genes guides clinicians to better treatment and prediction of prognosis for this rare disease. The present study aimed to evaluate genetic variants in ABCC8, KCNJ11, and HADH genes as causative genes for CHI in the Iranian population. METHODS: The present case series took place in Mashhad, Iran, within 11 years. Every child who had a clinical phenotype and confirmatory biochemical tests of CHI enrolled in this study. Variants in ABCC8, KCNJ11, and HADH genes were analyzed by the polymerase chain reaction and sequencing in our patients. RESULTS: Among 20 pediatric patients, 16 of them had variants in ABCC8, KCNJ11, and HADH genes. The mean age of genetic diagnosis was 18.6 days. A homozygous missense (c.2041-21G > A) mutation in the ABCC8 gene was seen in three infants. Other common variants were frameshift variants (c.3438dup) in the ABCC8 gene and a missense variant (c.287-288delinsTG) in the KCNJ11 gene. Most of the variants in our population were still categorized as variants of unknown significance and only 7 pathogenic variants were present. CONCLUSION: Most variants were located in the ABCC8 gene in our population. Because most of the variants in our population are not previously reported, performing further functional studies is warranted.

Clinical Efficacy Evaluation of Sirolimus in Congenital Hyperinsulinism.

BACKGROUND: Congenital hyperinsulinism (CHI) is a rare and life-threatening genetic disorder. Sirolimus as a mammalian target of rapamycin inhibitor may be helpful in patients with CHI who do not respond well to other treatments including diazoxide and octreotide. However, the safety and efficacy of this therapy are still unclear. This study aimed to evaluate the potential therapeutic effects of sirolimus in CHI patients with mutations in the ABCC8 and KCNJ11 genes. METHODS: During the period of this follow-up study, every child with a confirmed diagnosis of unresponsive CHI underwent genetic evaluation. Among those who had positive genetic testing, six families agreed to participate in this study. The participants were evaluated for ABCC8, KCNJ11, or HNF4α gene mutations by polymerase chain reaction (PCR) sequencing. The participants who were unresponsive to diazoxide and octreotide therapy received 0.5 mg/m2/d of sirolimus, and the dose was gradually increased until a serum concentration of 5-15 ng/ml was achieved. Then, the participants were followed up for any possible complications. RESULTS: Among the study participants, only one neonate was completely free of hypoglycemia after one year of follow-up, whereas three others experienced a partial reduction in hypoglycemic episodes over six months. One neonate underwent pancreatectomy despite receiving sirolimus. The oldest participant with a mutation in the ABCC8 gene responded well to sirolimus therapy after surgery and remained asymptomatic for 18 months. CONCLUSION: This study suggested that sirolimus therapy needs further evaluation to determine which patients will benefit the most. The genetic basis of CHI may have possible implications for determining the patient's response.

Folate targeted PEGylated liposomes for the oral delivery of insulin: In vitro and in vivo studies.

In this study using phospholipids with high transition temperature and taking advantage of PEGylation, we designed liposomal formulation targeted with folic acid (FA) to improve the stability of liposomes with high penetration efficiency at the same time. The results of characterization demonstrated that liposomal formulations are in range of 150-210 nm size with negative surface charge. The results of cell uptake indicated that FA conjugation resulted in the more uptake of insulin. However, the results of transepithelial electrical resistance (TEER) showed no statistical differences among the formulations. The results of biodistribution also demonstrated that PEGylated liposome targeted with FA had more residence time in stomach and intestine along with higher amounts in blood and liver. The anti-diabetic effects of formulation in vivo indicated the efficacy of PEGylated liposome targeted with FA had promising results in decreasing blood glucose and increasing insulin levels. The results of this study indicated that using phospholipids with high Tm along with PEGylation and using targeting ligand could improve efficiency of oral delivery of liposomes which merit further investigation.

Novel DNA variation of GPR54 gene in familial central precocious puberty.

BACKGROUND: Puberty can be considered the end point of a maturation process which is defined by the dynamic interactions of genes and environmental factors during prenatal and postnatal development. Kisspeptin/G protein-coupled receptor-54, is as an essential gatekeeper and regulator of GnRH neurons, and a key factor in initiation of puberty. Loss and gain of functional mutations in the GPR54 gene are associated with hypogonadotropic hypogonadism and precocious puberty, respectively. This study was designed to evaluate variations of GPR54 in familial precocious puberty. METHODS: Genomic DNA was extracted from peripheral whole blood of 25 subjects with familial precocious puberty. Coding exons 1-5 of the GPR54 gene were amplified by polymerase chain reaction (PCR) and the PCR products were purified and sequenced. DNA sequences were compared to the human GenBank GPR54 sequence using Sequencher sequence alignment software. RESULTS: We detected three different Single Nucleotide Polymorphisms (SNPs) in GPR54: rs10407968 (24A > T) in 13 subjects (52%); rs3050132 (1091 T > A) in 16 subjects (64%), and a novel polymorphism (492C > G) in one subject (4%), while three subjects (12%) had no SNPs. No mutations were found in the GPR54 gene. CONCLUSIONS: Regarding the presence of SNPs in 88% of the subjects in this study, it is likely a relationship exists between the SNPs of the GPR54 gene and familial precocious puberty. Further research is needed to investigate this possibility, and potential functional effects of these polymorphisms.

Wolcott-Rallison syndrome in Iran: a common cause of neonatal diabetes.

Background Wolcott-Rallison syndrome is a rare autosomal recessive disorder characterized by neonatal/early-onset non-autoimmune insulin-dependent diabetes, multiple epiphyseal dysphasia and growth retardation. It is caused by mutations in the gene encoding eukaryotic translation initiation factor 2α kinase 3 (EIF2AK3). We aimed to study the clinical characteristics and frequency of the disease in the Iranian population. Methods We recruited 42 patients who referred to the endocrine and metabolism clinic at Mashhad Imam Reza Hospital with neonatal diabetes. Molecular screening of KCNJ11, INS, ABCC8 and EIF2AK3 was performed at the Exeter Molecular Genetics Laboratory, UK. We calculated the frequency of the disease in 124 patients referred from Iran to the Exeter Molecular Genetics Laboratory for genetic screening and compared it to other countries worldwide. Results We identified seven patients as having Wolcott-Rallison syndrome. Genetic testing confirmed the clinical diagnosis and indicated five novel mutations. Only two patients developed clinical features of the syndrome by 6 months of age. Of all 124 cases of Iranian neonatal diabetes referred to the Exeter Molecular Genetics Laboratory for genetic screening, 28 patients (22.58%) had a recessive mutation in EIF2AK3. Conclusions The results of this study raises awareness of the condition and provides further accurate data on the genetic and clinical presentation of Wolcott-Rallison syndrome in the Iranian population. Our study highlights the importance of genetic testing in patients from consanguineous families with diabetes diagnosed within the first 6 months of life.

Novel mutation in AIRE gene with autoimmune polyendocrine syndrome type 1.

PURPOSE: Autoimmune polyendocrine type 1 (APS-1) is a complex inherited autosomal recessive disorder. Classically, it appears within the first decade of life followed by adrenocortical insufficiency, mucocutaneous candidiasis, Addison's disease, and hypoparathyroidism. The clinical phenotype of APS-1 varies depending upon mutations in the autoimmune regulator gene (AIRE) on chromosome 21q22.3. METHODS: In this study, we performed Sanger sequencing ofAIRE in Iranian patients to identify different variants and probable new mutations corresponding to a clinical diagnosis of APS-1. RESULTS: After analyzing 14AIRE exons, we detected a novel insertion mutation in exon 2 in a patient who presented with severe APS-1, Lys50AsnfsX168. Furthermore, the known mutations in AIRE, including Arg139X, Arg257X, and Leu323SerfsX51, were detected in enrolled patients. DISCUSSION: According to our results, sequencing analysis ofAIRE provides a useful screening method to diagnose patients with incomplete or unusual clinical presentations of APS-1.

Niemann-Pick Diseases: The Largest Iranian Cohort with Genetic Analysis.

OBJECTIVES: Niemann-Pick diseases (NPD) is an autosomal recessive inherited lysosomal lipid storage disorder which occurs due to a defect in cellular cholesterol trafficking, leading to excess lipid accumulation in multiple organ systems such as the brain, lungs, spleen, and liver. SPMD1-associated disease includes classic infantile and visceral NPD type A and B respectively. Type C NPD is subacute or juvenile. MATERIALS & METHODS: During 2012-2016, the patients who had the clinical and biochemical signs and symptoms of different types of NPD, underwent genetic analysis. All patients were collected from five provinces in Iran (Razavi Khorasan, South Khorasan, Khozaestan, Isfahan and Tehran province). Sanger sequencing of the candidate genes for NPD was performed followed by bioinformatics analysis to confirm the types of NPD and to identify novel mutations. All patients underwent full clinical assessment. RESULTS: We present two cases with NPD type A, six cases with NPD type B, and 11 cases with type C with various enzymatic defects identified in these cases. Within these 19 patients, we present 9 previously reported mutations and 10 novel mutations causing NPD. CONCLUSION: This study is the largest Iranian study for NPD analysis ever. Our report demonstrates that NPD has a variable age of onset and can present early in life. We investigated the clinical and genetic manifestations of a large Iranian cohort. Understanding the variable presentation of NPD will allow for clinicians to have a high index of suspicion for the disease.