Background Premature ovarian failure (POF) is characterized by the loss of ovarian activity before the age of 40 years. Stem cell therapy has the capability to create a regenerative microenvironment and is a proposed treatment for POF-related infertility due to the presence of renewal folliculogenesis and germ cells in the adult ovaries. In this study, we assessed the safety, feasibility, efficacy and dose adjustment of autologous adipose-derived stromal cells (ADSCs) and their ability to improve ovarian function in POF patients. Methods This study was a non-randomized clinical trial, phase I. Nine women with a definitive diagnosis of POF were divided into three groups (n = 3 per group) that received either 5 × 106, 10 × 106, or 15 × 106 autologous ADSCs suspension transplanted in the one ovary. Participants were followed-up at 24 h after the transplantation, and at 1 and 2 weeks, and 1, 2, 3, 6, and 12 months after the transplantation. The primary objective was to evaluate the safety of ADSCs transplantation. Secondary objectives included the effects of ADSCs transplantation on the resumption of menstruation, hormones level (Follicle-stimulating hormone (FSH) and anti-Müllerian hormone), ovarian function (Antral follicle count and ovary volume by ultrasonography evaluation) as well as dose escalation. Results Participants had not shown any early-onset possible side effects and secondary complications during follow-up. The menstruation resumption was observed in four patients which established for several months. In the 15 × 106 group, two POF patients had a return of menstruation second months after the intervention. Two other POF patients in 5 × 106 and 10 × 106 cell groups reported menstruation resumption at 1 month after the intervention. We observed decreased serum FSH levels of less than 25 IU/l in four patients. In two patients in 5 × 106 and 10 × 106 cell groups, serum FSH showed an inconsistent decline during a 1 year follow up after ADSCs transplantation. The ovarian volume, AMH, and AFC were variable during the follow-up and no significant differences between cell groups (p > 0.05). Conclusions We showed the intra-ovarian embedding of ADSCs is safe and feasible and is associated with an inconsistent decline in serum FSH. This should be further investigated with a large RCT. Trial registration NCT02603744, Registered 13 November 2015 - Retrospectively registered, http://www.Clinicaltrials.gov

STUDY QUESTION Can whole-exome sequencing (WES) reveal a shared pathogenic variant responsible for primary gonadal failure in both male and female patients from a consanguineous family? SUMMARY ANSWER Patients with primary ovarian insufficiency (POI) and non-obstructive azoospermia (NOA) were homozygous for the rare missense variant p. S754L located in the highly conserved MSH4 MutS signature motif of the ATPase domain. An oligozoospermic patient was heterozygous for the variant. WHAT IS KNOWN ALREADY MSH4 is a meiosis-specific protein expressed at a certain level in the testes and ovaries. Along with its heterodimer partner MSH5, it is responsible for double-strand Holliday junction recognition and stabilization, to ensure accurate chromosome segregation during meiosis. Knockout male and female mice for Msh4 and Msh5 are reportedly infertile due to meiotic arrest. In humans, MSH4 is associated with male and female gonadal failure, with distinct variations in the MutS domain V. STUDY DESIGN, SIZE, DURATION This was a retrospective genetics study of a consanguineous family with multiple cases of gonadal failure in both genders. The subject family was recruited in Iran, in 2018. PARTICIPANTS/MATERIALS, SETTING, METHODS The proband who is affected by POI, an NOA brother, a fertile sister and their parents were subjected to WES. The discovered variant was validated in these individuals, and the rest of the family was also genotyped by Sanger sequencing. The variant was not detected in 800 healthy Iranian individuals from the Iranome database nor in 30 sporadic NOA and 30 sporadic POI patients. Suggested effect in aberrant splicing was studied by RT-PCR. Moreover, protein homology modeling was used to further investigate the amino acid substitution in silico. MAIN RESULTS AND THE ROLE OF CHANCE The discovered variant is very rare and has never been reported in the homozygous state. It occurs in the ATPase domain at Serine 754, the first residue within the highly conserved MutS signature motif, substituting it with a Leucine. All variant effect prediction tools indicated this variant as deleterious. Since the substitution occurs immediately before the Walker B motif at position 755, further investigations based on protein homology were conducted. Considering the modeling results, the nature of the substituted amino acid residue and the distances between p. S754L variation and the residues of the Walker B motif suggested the possibility of conformational changes affecting the ATPase activity of the protein. LARGE SCALE DATA We have submitted dbSNP entry rs377712900 to ClinVar under SCV001169709, SCV001169708 and SCV001142647 for oligozoospermia, NOA and POI, respectively. LIMITATIONS, REASONS FOR CAUTION Studies in model organisms can shed more light on the role of this variant as our results were obtained by variant effect prediction tools and protein homology modeling. WIDER IMPLICATIONS OF THE FINDINGS Identification of variants in meiotic genes should improve genetic counseling for both male and female infertility. Also, as two of our NOA patients underwent testicular sperm extraction (TESE) with no success, ruling out the existence of pathogenic variants in meiotic genes in such patients prior to TESE could prove useful. STUDY FUNDING/COMPETING INTEREST(S) This study was financially supported by Royan Institute in Tehran, Iran, and Institut Pasteur in Paris, France. The authors declare no competing interests. TRIAL REGISTRATION NUMBER N/A

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