Androgen Insensitivity Syndrome DUE to Non-Coding Variation in the Androgen Receptor Gene: Review of the Literature and Case Report of a Patient with Mosaic c.-547C>T Variant.

Sexual development (SD) is a complex process with strict spatiotemporal regulation of gene expression. Despite advancements in molecular diagnostics, disorders of sexual development (DSD) have a diagnostic rate of ~50%. Androgen insensitivity syndrome (AIS) represents the most common form of 46,XY DSD, with a spectrum of defects in androgen action. Considering the importance of very strict regulation of the SD, it is reasonable to assume that the genetic cause for proportion of the DSD lies in the non-coding part of the genome that regulates proper gene functioning. Here we present a patient with partial AIS (PAIS) due to a mosaic de novo c.-547C>T pathogenic variant in the 5'UTR of androgen receptor (AR) gene. The same mutation was previously described as inherited, in two unrelated patients with complete AIS (CAIS). Thus, our case further confirms the previous findings that variable gene expressivity could be attributed to mosaicism. Mutations in 5'UTR could create new upstream open reading frames (uORFs) or could disrupt the existing one. A recent systematic genome-wide study identified AR as a member of a subset of genes where modifications of uORFs represents an important disease mechanism. Only a small number of studies are reporting non-coding mutations in the AR gene and our case emphasizes the importance of molecular testing of the entire AR locus in AIS patients. The introduction of new methods for comprehensive molecular testing in routine genetic diagnosis, accompanied with new tools for in sillico analysis could improve the genetic diagnosis of AIS, and DSD in general.

Two Brothers from Macedonia with Gitelman Syndrome.

Gitelman syndrome (GS) is a rare renal tubulopathy with an autosomal recessive mode of inheritance, caused by biallelic pathogenic variants in the SLC12A3 gene. The clinical features may overlap with other disorders, such as Bartter syndrome type 3, HNF1B nephropathy or even mitochondrial disease, but can be distinguished by molecular genetic analysis. Here we report on two preschool brothers, who presented with a several months' history of episodes of carpopedal spasms and muscle aches. The biochemical analyses revealed hypokalemia and hypomagnesemia without metabolic alkalosis. A 24-h urine sample demonstrated hypocalciuria. The molecular analyses showed that both patients were heterozygous for 3 (likely) pathogenic variants in SLC12A3: c.1805_1806del; p. (Tyr602Cysfs*31), c.2660+1G>A and c.2944 A>T; p. (Ile982Phe). Analysis of the parents showed that the mother was heterozygous for the c.2944 A>T p.(Ile982Phe) variant, and the father carried the other 2 variants (c.1805_1806del and c.2660+1G>A). Herein we present two children in a family from N. Macedonia with clinical manifestations and electrolyte imbalances suggestive of GS. The results of the tubulopathy next generation sequencing (NGS) panel confirmed the diagnosis. The boys are treated with a high salt diet and oral potassium and magnesium supplements.

Chromosomal Abnormalities in Early Pregnancy Losses: A Study of 900 Samples.

Chromosomal abnormalities are the most common causes of early pregnancy losses (EPLs). In this study, we aimed to evaluate the incidence and spectrum of chromosomal abnormalities in EPLs and correlate them with different clinical characteristics. We performed Quantitative Fluorescent PCR (QF-PCR), followed by subtelomeric Multiplex Ligation Probe Amplification (MLPA) analysis to detect chromosomal abnormalities in 900 products of conceptions (POCs) from EPLs collected over a period of 10 years. Chromosomal abnormalities were present in 56.25% of uncontaminated EPLs, with significantly higher incidence in women ≥36 years (71.37%, p<0.0001) in comparison to women ≤30 years of age (43.40%). Trisomies were also more common in women ≥36 years (79.68%, p<0.0001) than in those ≤30 years of age (48.70%). In contrast, triploidy and monosomies were more prevalent in women ≤30 years of age (26.09%, p<0.0001 and 16.52%, p=0.0066 respectively) than in women ≥36 years of age (6.42% and 6.42% respectively). Trisomy 16 was more common in women ≤30 (39.29%, p=0.0009) than in those ≥36 years of age (16.78%), while trisomy 22 was predominant among women ≥36 (23.49%, p=0.013), and was not present in the group of women ≤30 years of age. The frequency of chromosomal abnormalities in POCs from women with sporadic (61.19%) was higher than in those with recurrent EPLs (55.21%). This difference, however, was not statistically significant (p=0.164). Although some differences in the chromosomal aneuploidy rates among women with different ABO blood groups, as well as among 6-8 and 9-11 gestational week EPLs were observed, further larger studies are required to confirm these findings. In conclusion, our study enriches the knowledge about chromosomal abnormalities as a cause of EPLs and confirms the higher incidence of foetal chromosomal abnormalities in EPLs in women of older reproductive age. Furthermore, it shows that using QF-PCR and MLPA methodologies, a high detection rate of chromosomal abnormalities in EPLs can be reached.

Two Years of Newborn Screening for Cystic Fibrosis in North Macedonia: First Experience.

There is a widely accepted consensus on the benefits of newborn screening (NBS) for cystic fibrosis (CF) in terms of reduced disease severity, improved quality of life, lower treatment burden, and reduced costs. More and more countries in the world are introducing NBS for CF as a national preventive health program. Newborn screening for CF was introduced in the Republic of North Macedonia (RNM) in April, 2019, after a pilot study of 6 months in 2018. A two-step immunoreactive trysinogen (IRT-IRT) algorithm is performed, and then a sweat test for confirmation/exclusion of the CF diagnosis when the IRT values were both over the cutoff (70.0 and 45.0 ng/mL, respectively). In cases with confirmed diagnosis of CF (a sweat chloride concentration >60.0 mmol/L) or with intermediate sweat test results (a sweat chloride concentration of between 30.0 and 59.0 mmol/L), CF transmembrane conductance regulator (CFTR) mutation analysis is performed. By the end of 2020, over a period of 27 months, including the pilot study period, a total number of 43,139 newborns were screened for CF. Seventeen (0.039%) newborns were diagnosed with CF. In all newly discovered CF cases by screening, the diagnosis was confirmed by determination of the CFTR mutations. The most common CFTR mutation, F508del, was found with an overall incidence of 70.6%. Other more frequent mutations were G542X (11.8%) and N1303K (5.9%). Four mutations were found in one CFTR allele each: G1349D, G126D, 457TAT>G and CFTRdupexon22, with the last one being newly discovered with unknown consequences. An incredibly large difference was found in the incidence of the disease between the Macedonian and Albanian neonatal population, with almost four time higher prevalence among Albanians (1:4530 vs. 1:1284).

de Novo TINF2 C.845G>A: Pathogenic Variant in Patient with Dyskeratosis Congenita.

Dyskeratosis congenita (DC) is a clinically and genetically heterogeneous, multisystem inherited syndrome with a very high risk for bone marrow failure (BMF) and cancer predisposition. The classical clinical form of DC is characterized by abnormal skin pigmentation, nail dystrophy, and oral leukoplakia. Bone marrow failure is considered to be an important and major complication of DC and the leading cause of death which develops in around 85% of cases. A number of genes involved in telomere maintenance are associated with DC, such as genes that encode the components of the telomerase complex (TERT, DKC1, TERC, NOP10, and NHP2), T-loop assembly protein (RTEL1), telomere capping (CTC1), telomere shelterin complex (TINF2), and telomerase trafficking protein (TCAB1). Mutations in TINF2 have been reported in 11-20% of all patients with DC and have been associated with bone marrow failure. Here we report on a 19-month old boy with very early presentation of bone marrow failure as a first clinical manifestation of DC. Upon first admission, the patient presented with thrombocytopenia and macrocytic anemia. Soon after, his blood counts deteriorated with the development of pancytopenia and aplastic anemia. Four months later, he developed nail dystrophy and skin hyperpigmentation. A de novo heterozygous pathogenic variant c.845G>A, p.(Arg282His) was located in exon 6 of TINF2 gene and was identified via clinical exome sequencing. The findings confirmed the diagnosis of DC. This is the first case with DC due to TINF2 pathogenic variant reported in North Macedonia.

Cystic Fibrosis Mutation Spectrum in North Macedonia: A Step Toward Personalized Therapy.

The most prevalent "rare" disease worldwide, cystic fibrosis (CF), is an autosomal recessive multisystem disease, caused by mutations in the CFTR gene. The knowledge of CFTR mutations present in certain population is important for designing a simple, fast and cost-effective genetic testing approach, also for better management of CF patients, including the administration of novel targeted therapies. Here, we present genetic results of 158 unrelated CF patients from the National CF Registry of the Republic of North Macedonia. Initially, patients were screened for the 11 most common CF mutations. Additional CF mutations and large deletions/duplications in the CFTR gene were analyzed using commercial kits. If the genotype was undetermined, all CFTR exons were analyzed using Sanger DNA sequencing or next generation sequencing (NGS) (since 2014). The most common CF mutation, c.l521_ 1523del (legacy name F508del), was found with an overall incidence of 75.9%. Additionally, 26 other pathogenic variants and three large deletions were identified in the CFTR gene as a genetic cause of CF. Two of these, c.1070 C>T (p.Ala357Val) and c.2779_2788dup CTTGCTATGG (p.Gly930AlafsTer48), were novel. According to the distribution and prevalence of the pathogenic variants detected in our patients, a fast and cost-effective method, based on a single base extension was designed as a first-line CF genetic test with a 90.0% detection rate within our population. Furthermore, the knowledge of CFTR mutation classes in our CF patients represents the first step toward personalized therapy for CF in our country.

Duplication of The SOX3 Gene in an Sry-negative 46,XX Male with Associated Congenital Anomalies of Kidneys and the Urinary Tract: Case Report and Review of the Literature.

Disorders of sex development (DSD) are a group of rare conditions characterized by discrepancy between chromosomal sex, gonads and external genitalia. Congenital abnormalities of the kidney and urinary tract are often associated with DSD, mostly in multiple malformation syndromes. We describe the case of an 11-year-old Caucasian boy, with right kidney hypoplasia and hypospadias. Genome-wide copy number variation (CNV) analysis revealed a unique duplication of about 550 kb on chromosome Xq27, and a 46,XX karyotype, consistent with a sex reversal phenotype. This region includes multiple genes, and, among these, SOX3 emerged as the main phenotypic driver. This is the fifth case reporting a genomic imbalance involving the SOX3 gene in a 46,XX SRY-negative male, and the first with associated renal malformations. Our data provide plausible links between SOX3 gene dosage and kidney malformations. It is noteworthy that the current and reported SOX3 gene duplications are below the detection threshold of standard karyotypes and were found only by analyzing CNVs using DNA microarrays. Therefore, all 46,XX SRY-negative males should be screened for SOX3 gene duplications with DNA microarrays.

Novel Genotype in Two Siblings with 5-α-reductase 2 Deficiency: Different Clinical Course due to the Time of Diagnosis.

Steroid 5-α-reductase-2 (5-ARD) deficiency is a result of mutations of the SRD5A2 gene. It causes the disorder of sexual differentiation (DSD) in 46,XY individuals with a variable genital phenotype. We present two siblings with female external genitalia at birth and bilateral inguinal testes, raised as females. These are the first molecularly characterized patients from the Republic of North Macedonia (RN Macedonia) with a different clinical course due to the time of the diagnosis. Diagnosis of Patient 1 was based upon the detection of bilateral inguinal testes and testosterone/dihidrotestosterone ratio. Sex reversal was initiated by testes removal at the age of 20 months. Breast implantation and vaginoplasty were performed in adolescence and the girl is comfortable with the female sex. Her sibling, Patient 2, raised as a girl, was clinically assessed at 11.5 years due to the growth of phalus, deep voice and Adam's apple enlargement. No change of gender was accepted. Complex molecular analysis including multiplex quantitative fluorescent polymerase chain reaction (PCR) screening for sex chromosome aneuploidies and SRY presence, Sanger sequencing combined with multiplex ligation-dependent probe amplification (MLPA), microarray-based comparative genomic hybridization (aCGH), and real-time PCR analysis for detection of exon copy number changes confirmed a novel c.146C>A (p.Ala49Asp) point mutation in the first exon inherited from the mother, and complete deletion of the first exon and adjacent regions inherited from the father. Novel genotype causing 5-ARD is presented. Genetic analysis is useful for the diagnosis and timely gender assignment in patients with 5-ARD. However, final gender assignment is difficult and requires combined medical interventions.

Molecular and Immunohistochemical Characteristics of Complete Hydatidiform Moles.

Molar pregnancy is a gestational trophoblastic disease that belongs to the category of precancerous lesions. On the other end of the spectrum are gestational trophoblastic neoplasms such as invasive mole, choriocarcinoma, placental site trophoblastic tumor and epithelioid trophoblastic tumor, which are considered malignant tumors. Based on defined histopathological criteria, molar pregnancy is divided into partial and complete hydatidiform mole. Especially in the case of early complete mole, the diagnosis can be quite challenging and often necessitates additional molecular or immunohistochemical methods. The aim of this study was to assess the importance of additional molecular and immunohistochemical methods to accurately diagnose complete hydatidiform mole and to stress the importance of correct diagnosis and close follow-up of these patients. A total of 367 consecutive cases of spontaneous abortion were analyzed in a 3-year period. Eight cases with histopathological diagnosis of complete molar pregnancy were selected for further analysis. Apart from standard microscopic analysis, additional molecular and immunohistochemical analyses were performed in all eight cases. Most of the histopathological characteristics of complete molar pregnancy were present in all cases, together with complete absence of positivity for the p57 immunohistochemical marker in the cytotrophoblasts and villous stromal cells. The molecular analysis revealed androgenetic diploidy in seven cases and biparental diploidy in one case with more than three consecutive complete molar pregnancies. Additional immunohistochemical and molecular methods can considerably aid in the correct diagnosis of molar pregnancy.

Genetic variation in leptin and leptin receptor genes as a risk factor for idiopathic male infertility.

The aim of this study was to examine whether there is an association among genetic variability in leptin (LEP) and leptin receptor (LEPR) genes and male infertility. We performed a case-control study and were searching for an association between polymorphisms of LEP and LEPR genes and male infertility. The study group consisted of 317 patients with idiopathic infertility and a control group of 241 fertile men from Slovenia. Four single nucleotide polymorphisms (SNPs) in LEP gene and four single nucleotide polymorphisms (SNPs) in LEPR gene were chosen and genotyped. Statistically significant SNP was further validated in additional 255 infertile patients and 168 controls from Serbia and Macedonia. In the Slovenian population, we found a statistically significant difference in genotype distribution for rs10244329 polymorphism in LEP gene (recessive genotype model, p value = 0.048). The trend toward statistically significant difference in genotype distribution for rs10244329 polymorphism was confirmed in the Serbian and Macedonian populations (p value = 0.07). Our data suggest that genetic variability in the LEP gene might be associated with male infertility warranting further confirmation and mechanistic investigations.

MicroRNA expression profiles in testicular biopsies of patients with impaired spermatogenesis.

Spermatogenesis is a complex process that involves thousands of genes whose expression during different stages is strictly regulated. Small non-coding microRNAs play an important role in the posttranscriptional regulation of mRNA processing during spermatogenesis. Using Agilent SurePrint v16 microRNA 8 × 60 K microarray kit, we investigated the microRNA expression profiles of 24 formalin-fixed paraffin-embedded testicular biopsies from patients with hypospermatogenesis (n = 10), hypospermatogenesis and azoospermia factor c region on the Y chromosome (AZFc) deletion (n = 3), Sertoli cell-only syndrome (n = 3) and maturation arrest (n = 2), in comparison with subjects with normal spermatogenesis (n = 6). After adjusting for multiple testing, six deregulated miRNAs were detected in the patients with AZFc deletion, 30 in maturation arrest group, 52 in Sertoli cell-only syndrome group of patients, and none in the group of patients with hypospermatogenesis. Some of the deregulated microRNAs were shared between groups, resulting in 58 unique differentially expressed microRNAs. The expression of five microRNAs (hsa-miR-34b, hsa-miR-449b, hsa-miR-517c, hsa-miR-181c, and hsa-miR-605) was validated by qRT-PCR in a total of 74 samples. Using mRNA expression profiles of subjects with matching histopathological patterns of impaired spermatogenesis from publically available Gene Expression Omnibus data sets, we have performed integrated mRNA-microRNA regulatory network analysis. Pathway analysis revealed significantly enriched set of genes for tumor necrosis factor-related apoptosis-inducing ligand signaling pathway, previously shown to be involved in regulation of apoptosis in normal functioning testis. Our results should be considered as preliminary as we have analyzed only a small number of patients in each studied group. Further studies with larger number of patients with impaired spermatogenesis as well as more targeted approaches with parallel microRNA and mRNA expression profiling in isolated subpopulations of somatic or germ cells from different stages of spermatogenesis are needed to clarify the role of the microRNAs in the process of spermatogenesis.

Clinical relevance of CHEK2 and NBN mutations in the macedonian population.

Clinical importance of the most common CHEK2 (IVS2+1 G>A, 1100delC, I157T and del5395) and NBN (R215W and 657del5) gene mutations for breast cancer development in Macedonian breast cancer patients is unknown. We performed a case-control study including 300 Macedonian breast cancer patients and 283 Macedonian healthy controls. Genotyping was done using a fast and highly accurate single-nucleotide primer extension method for the detection of five mutations in a single reaction. The detection of the del5395 was performed using an allele-specific duplex polymerase chain reaction (PCR) assay. We have found that mutations were more frequent in breast cancer patients (n = 13, 4.3%) than in controls (n = 5, 1.8%), although without statistical significance. Twelve patients were heterozygous for one of the analyzed mutations, while one patient had two mutations (NBN R215W and CHEK2 I157T). The most frequent variant was I157T, found in 10 patients and four controls (p = 0.176) and was found to be associated with familial breast cancer (p = 0.041). CHEK2 1100delC and NBN 657del5 were each found in one patient and not in the control group. CHEK2 IVS2+1G>A and del5395 were not found in our cohort. Frequencies of the studied mutations are low and they are not likely to represent alleles of clinical importance in the Macedonian population.

CYP2D6 allele distribution in Macedonians, Albanians and Romanies in the Republic of Macedonia.

Cytochrome P450 2D6 (CYP2D6) is an enzyme of great importance for the metabolism of clinically used drugs. More than 100 variants of the CYP2D6 gene have been identified so far. The aim of this study was to investigate the allele distribution of CYP2D6 gene variants in 100 individuals of each of the Macedonian, Albanian and Romany population, by genotyping using long range polymerase chain reaction (PCR) and a multiplex single base extension method. The most frequent variants and almost equally distributed in the three groups were the fully functional alleles *1 and *2. The most common non functional allele in all groups was *4 that was found in 22.5% of the Albanians. The most common allele with decreased activity was *41 which was found in 23.0% of the Romany ethnic group, in 11.0% of the Macedonians and in 10.5% of the Albanians. Seven percent of the Albanians, 6.0% of the Romani and 4.0% of the Macedonians were poor metabolizers, while 5.0% of the Macedonians, 1.0% of Albanians and 1.0% of the Romanies were ultrarapid metabolizers. We concluded that the CYP2D6 gene locus is highly heterogeneous in these groups and that the prevalence of the CYP2D6 allele variants and genotypes in the Republic of Macedonia is in accordance with that of other European populations.

NGS nominated CELA1, HSPG2, and KCNK5 as candidate genes for predisposition to Balkan endemic nephropathy.

Balkan endemic nephropathy (BEN) is a familial chronic tubulointerstitial disease with insidious onset and slow progression leading to terminal renal failure. The results of molecular biological investigations propose that BEN is a multifactorial disease with genetic predisposition to environmental risk agents. Exome sequencing of 22 000 genes with Illumina Nextera Exome Enrichment Kit was performed on 22 DNA samples (11 Bulgarian patients and 11 Serbian patients). Software analysis was performed via NextGene, Provean, and PolyPhen. The frequency of all annotated genetic variants with deleterious/damaging effect was compared with those of European populations. Then we focused on nonannotated variants (with no data available about them and not found in healthy Bulgarian controls). There is no statistically significant difference between annotated variants in BEN patients and European populations. From nonannotated variants with more than 40% frequency in both patients' groups, we nominated 3 genes with possible deleterious/damaging variants--CELA1, HSPG2, and KCNK5. Mutant genes (CELA1, HSPG2, and KCNK5) in BEN patients encode proteins involved in basement membrane/extracellular matrix and vascular tone, tightly connected to process of angiogenesis. We suggest that an abnormal process of angiogenesis plays a key role in the molecular pathogenesis of BEN.

Study of Three Single Nucleotide Polymorphisms in the SLC6A14 Gene in Association with Male Infertility.

Although several genetic causes of male infertility are known, the condition in around 60.0-75.0% of infertile male patients appears to be idiopathic. In some, genetic causes may be polygenic and require several low-penetrance genes to produce a phenotype outcome. In others, pleiotropy, when a gene can produce several phenotypic traits, may be involved. We have investigated whether single nucleotide polymorphisms (SNPs) in the SLC6A14 [solute carrier family 6 (amino acid transporter), member 14] gene are associated with male infertility. This gene has previously been linked with obesity and cystic fibrosis, which are associated with male infertility. It has a role in the transport of tryptophan and synthesis of serotonin that are important for normal spermatogenesis and testicular function. We have analyzed three SNPs (rs2312054, rs2071877 and rs2011162) in 370 infertile men and 241 fertile controls from two different populations (Macedonian and Slovenian). We found that the rs2011162(G) allele and rs2312054(A)-rs2071877(C)-rs2011162(G) haplotype are present at lower frequencies in the infertile rather than the fertile men (p = 0.044 and p = 0.0144, respectively). We concluded that the SLC6A14 gene may be a population-specific, low-penetrance locus which confers susceptibility to male infertility/subfertility. Additional follow-up studies of a large number of infertile men of different ethnic backgrounds are needed to confirm such a susceptibility.

A Homozygous Deletion of the DPY19l2 Gene is a Cause of Globozoospermia in Men from the Republic of Macedonia.

Globozoospermia is a rare but severe teratozoospermia, characterized by ejaculates consisting completely of round-headed spermatozoa that lack an acrosome or, in partial globozoospermia, containing a variable proportion (20.0-90.0%) of acrosomeless spermatozoa. Men that are affected with total globozoospermia are infertile, and even the application of intracytoplasmic sperm injection (ICSI) has met with disappointingly low success rates. In humans, several case reports of globozoospermia have demonstrated that two or more siblings were affected in each family, which suggested a genetic component to this disease. Currently, three genes are known to be associated with total globozoospermia in humans, SPATA16 , PICK1 and DPY19L2 genes. Mutations in SPATA16 and PICK1 are rare causes of globozoospermia, found in only one patient each. Several studies have suggested that DPY19L2 mutations are the major cause of globozoospermia in patients from different ethnic origins and different geographic regions. The most common DPY19L2 mutation is the 200 kb deletion arising from a nonallelic homologous recombination (NAHR) between the flanking low copy repeats (LCRs). Here we describe the presence of a homozygous deletion of the DPY19L2 gene in two infertile Macedonian patients with 100.0% round headed spermatozoa, thus suggesting that this deletion represents a major cause of globozoospermia among Macedonian men.

Proteomic analysis of seminal plasma in men with different spermatogenic impairment.

Seminal plasma is a potential source of biomarkers for many disorders of the male reproductive system including male infertility. The identification and characterisation of differentially expressed proteins in seminal plasma of man with normal and impaired spermatogenesis can help in the elucidation of the molecular basis of male infertility. We compared the protein expression profiles of seminal plasma from four different groups of men as follows: normozoospermic, asthenozoospermic, oligozoospermic and azoospermic groups, using two-dimensional differential gel electrophoresis (2-D DIGE). We found eight proteins with statistically significant increased expression in azoospermia compared with at least one of the other studied groups. The differentially expressed spots were fibronectin, prostatic acid phosphatase (PAP), proteasome subunit alpha type-3, beta-2-microglobulin, galectin-3-binding protein, prolactin-inducible protein and cytosolic nonspecific dipeptidase. Notably, PAP was increased in patients with azoospermia compared with that of all other groups. We have observed no statistically significant differences in protein expression between three of the groups: normozoospermic, oligozoospermic and asthenozoospermic. We suggest that the identified panel of proteins in our study especially PAP have a strong potential to be used as azoospermia markers. However, further investigations will be necessary to validate these markers in samples of larger and independent patient cohorts and to clarify their role in the pathogenesis of male infertility.

CAG Repeat Number in the Androgen Receptor Gene and Prostate Cancer.

Prostate cancer (PC) is the second leading cause of cancer deaths in men. The effects of androgens on prostatic tissue are mediated by the androgen receptor (AR) gene. The 5' end of exon 1 of the AR gene includes a polymorphic CAG triplet repeat that numbers between 10 to 36 in the normal population. The length of the CAG repeats is inversely related to the transactivation function of the AR gene. There is controversy over association between short CAG repeat numbers in the AR gene and PC. This retrospective case-control study evaluates the possible effect of short CAG repeats on the AR gene in prostate cancer risk in Macedonian males. A total of 392 male subjects, 134 PC patients, 106 patients with benign prostatic hyperplasia (BPH) and 152 males from the general Macedonian population were enrolled in this study. The CAG repeat length was determined by fluorescent polymerase chain reaction (PCR) amplification of exon1 of the AR gene followed by capillary electrophoresis (CE) on a genetic analyzer. The mean repeat length in PC patients was 21.5 ± 2.65, in controls 22.28 ± 2.86 (p = 0.009) and in BPH patients 22.1 ± 2.52 (p = 0.038). Short CAG repeats (<19) were found in 21.64% of PC patients vs. 9.43% in BPH patients (p = 0.0154). We also found an association of low Gleason score (<7) with short CAG repeat (<19) in PC patients (p = 0.0306), and no association between the age at diagnosis of PC and BPH and CAG repeat length. These results suggest that reduced CAG repeat length may be associated with increased prostate cancer risk in Macedonian men.