RESUMO
BACKGROUND: The main genetic cause of iron overload is haemochromatosis (HC). In recent years, the study of non-HFE genes (HFE2, HJV, HAMP, TRF2, SLC40A1, and BMP6) has become relevant thanks to next-generation sequencing (NGS) and multiplex ligation-dependent probe amplification (MLPA) techniques. Our objectives were to estimate the prevalence of both HFE (C282Y/HY63D variants) and non-HFE variants attending a tertiary hospital in Aragón, to predict the effect of the variants on the protein, and to establish a genotype-phenotype correlation evaluating with the clinical context. METHODS: Retrospective descriptive study from 2006 to 2020 of patients attended at genetic consultation in a reference hospital for HC in Aragon. We calculated prevalence of HFE and non-HFE variants. We analysed non-HFE genes (HFE2, HJV, HAMP, TRF2, SLC40A1, and BMP6), used bioinformatics tools, consulted different databases and measured clinical parameters (laboratory and imaging). RESULTS: The prevalence of C282Y homozygous was 5.95% respect the total of cases and 0.025% respect our population. The prevalence of non-HFE HC variants was 1.94% respect the total of cases and 0.008% respect our population. We found 27 variants in non-HFE genes and 4 in HFE gene, of which 6 were classified as variant of uncertain clinical significance (VUS), or likely pathogenic or pathogenic according to the ACMG classification criteria. CONCLUSION: Our prevalence results are as expected, and similar to those obtained by other studies. Although some of the genetic findings explain the clinical symptoms of some of our patients, we remain have a high number of patients without a clear molecular diagnosis.
RESUMO
BACKGROUND AND OBJECTIVE: The presence of microdeletions in the Y-chromosome azoospermia factor (AZF) region (YCMs) is considered the most frequent genetic cause of male infertility along with Klinefelter syndrome. The objective of this study was to investigate the frequencies and type of YCMs in infertile men in Aragon and to analyze the relationship between sex hormones, sperm count and microdeletions in them. PATIENTS AND METHODS: Retrospective descriptive study of 644 men who during 2006-2019 were screened for YCMs using YChromStrip (Operón, Spain) by PCR+reverse hybridization, spermiogram, karyotype and quantification of sex hormones. RESULTS: The frequency of YCMs was 3.88% (25/644), not being detected in any patient with mild or normospermic oligozoospermia, that is, in sperm counts higher than 5×106/mL. The group of azoospermic patients was the one that presented a higher frequency of YCMs (14.58%, 14/96). Deletions in the AZFc region were the most frequent (68%). 20% (5/25) of patients with YCMs also presented some type of karyotype abnormality that included aneuploidies, deletions, duplications and/or translocations. Sperm count was significantly lower and FSH and LH concentrations significantly higher in the group of patients with YCMs. CONCLUSIONS: YCMs screening is a key test in the diagnostic approach to male infertility. Obtaining an adequate result allows choosing suitable assisted reproduction techniques, preventing unnecessary treatments and the transmission of genetic defects to offspring.