Renal agenesis-related genes are associated with Herlyn-Werner-Wunderlich syndrome

Ectopic urethral opening in herlyn-werner-wunderlich syndrome: A rare finding

Recorded findings of Herlyn-Werner-Wunderlich Syndrome (HWWS) remain sparse due to low statistical incidence. Ours is also the first known case to present with an ectopic urethral opening, an even rarer complication. A 27-year-old nulliparous woman presented with complaints of cyclical hematuria, and burning micturition with intermittent episodes of urinary retention suprapubic and pelvic pain. After extensive radiological examination, the MRI findings concluded the presence of a uterine didelphys with 2 cervixes and vaginal duplication marked by the compression of the left hemivagina and dilation of the right hemivagina, pointing towards HWWS. The case strongly suggests that the presence of an ectopic urethral opening may be the cause of urinary incontinence and discomfort in an otherwise asymptomatic patient of HWWS.

Pathophysiology of Congenital Anomalies of the Kidney and Urinary Tract: A Comprehensive Review

Congenital anomalies of the kidney and urinary tract (CAKUT) represent a broad range of diseases with differing mechanisms, clinical presentations, and prognoses. With an estimated prevalence of between 4 and 60 per 10,000 births, CAKUT represents a sizable number of patients for pediatric and adult nephrologists as therapies have progressed, allowing longer life spans. Many CAKUT disorders are associated with genetic mutations, and with advances in genomic sequencing, these genes are being identified at an increasing rate. Understanding these mutations provides insight into these conditions' molecular mechanisms and pathophysiology. In this article, we discuss the epidemiology, presentation, and outcomes of CAKUT in addition to our current understanding of genetic and molecular mechanisms in these diseases.

Identification and functional characteristics of CHD1L gene variants implicated in human Müllerian duct anomalies

BACKGROUND

Müllerian duct anomalies (MDAs) are congenital developmental disorders that present as a series of abnormalities within the reproductive tracts of females. Genetic factors are linked to MDAs and recent advancements in whole-exome sequencing (WES) provide innovative perspectives in this field. However, relevant mechanism has only been investigated in a restricted manner without clear elucidation of respective observations.

METHODS

Our previous study reported that 2 of 12 patients with MDAs harbored the CHD1L variant c.348-1G>C. Subsequently, an additional 85 MDAs patients were recruited. Variants in CHD1L were screened through the in-house database of WES performed in the cohort and two cases were identified. One presented with partial septate uterus with left renal agenesis and the other with complete septate uterus, duplicated cervices and longitudinal vaginal septum. The pathogenicity of the discovered variants was further assessed by molecular dynamics simulation and various functional assays.

RESULTS

Ultimately, two novel heterozygous CHD1L variants, including a missense variant c.956G>A (p.R319Q) and a nonsense variant c.1831C>T (p.R611*) were observed. The variants were absent in 100 controls. Altogether, the contribution yield of CHD1L to MDAs was calculated as 4.12% (4/97). All three variants were assessed as pathogenic through various functional analysis. The splice-site variant c.348-1G>C resulted in a 11 bp sequence skipping in exon 4 of CHD1L and led to nonsense mediated decay of its transcripts. Unlike WT CHD1L, the truncated R611* protein mislocalized to the cytoplasm, abolish the ability of CHD1L to promote cell migration and failed to interact with PARP1 owing to the loss of macro domain. The R319Q variant exhibited conformational disparities and showed abnormal protein recruitment behavior through laser microirradiation comparing with the WT CHD1L. All these variants impaired the CHD1L function in DNA damage repair, thus participating in MDAs.

CONCLUSIONS

The current study not only expands the mutational spectrum of CHD1L in MDAs but determines three variants as pathogenic according to ACMG guidelines with reliable functional evidence. Additionally, the impairment in DNA damage repair is an underlying mechanism involved in MDAs.

POI-associated EIF4ENIF1 mutations exhibit impaired translation regulation abilities

Various genetic variants have been found to be associated with the clinical onset of premature ovarian insufficiency (POI). However, when measured in vitro, the functional influence of the variants can be difficult to determine. By whole-exome sequencing (WES) of 93 patients with sporadic POI, we found a missense variant c.623G > A;p.R208H in the EIF4ENIF1 gene. In silico prediction of the variant using different algorithms suggested it might be a damaging variant. We compared the property of EIF4ENIF1 R208H and Q842P, a POI-related mutant that we reported previously, with wildtype (WT) protein using 293FT cells in vitro. Surprisingly, a change in subcellular distribution and granule forming ability (Q842P) and nuclear import capacity (R208H) was not observed, despite domain prediction evidences. Since EIF4ENIF1 was reported to inhibit translation, we employed T&T-seq, a translation-transcription dual-omics sequencing method, to profile gene expression upon overexpression of EIF4ENIF1 WT and mutants. EIF4ENIF1 WT overexpression group exhibited significantly (P < 0.0001) lower translation efficiency (TE) than empty vector or GFP overexpression control group. Surprisingly, EIF4ENIF1 Q842P overexpression failed to repress global translation, showing an overall TE significantly higher than WT group. Overexpression R208H significantly (P < 0.0001) lowered the overall TE, whereas exhibiting a reduced translation inhibitory effect on high-TE genes (TE > 2 in GFP control group). Several fertility-associated genes, such as AMH in Q842P group and SERPINE1 and THBS1 in R208H group, was translationally up-regulated in mutant groups versus WT control, suggesting a potential mechanism of mutated EIF4ENIF1 causing POI via impaired translation repression. It is further proposed that T&T-seq can be a sensitive evaluation tool for the measurement of functional alteration by variants in many other translational regulator genes, not only EIF4ENIF1, helping to eliminate misinterpretation of clinical significance of genetic variants.

Genetics of Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome: advancements and implications

Mayer-Rokitansky-Küster-Hauser (MRKH) syndrome is a congenital anomaly characterized by agenesis/aplasia of the uterus and upper part of the vagina in females with normal external genitalia and a normal female karyotype (46,XX). Patients typically present during adolescence with complaints of primary amenorrhea where the diagnosis is established with significant implications including absolute infertility. Most often cases appear isolated with no family history of MRKH syndrome or related anomalies. However, cumulative reports of familial recurrence suggest genetic factors to be involved. Early candidate gene studies had limited success in their search for genetic causes of MRKH syndrome. More recently, genomic investigations using chromosomal microarray and genome-wide sequencing have been successful in detecting promising genetic variants associated with MRKH syndrome, including 17q12 (LHX1, HNF1B) and 16p11.2 (TBX6) deletions and sequence variations in GREB1L and PAX8, pointing towards a heterogeneous etiology with various genes involved. With uterus transplantation as an emerging fertility treatment in MRKH syndrome and increasing evidence for genetic etiologies, the need for genetic counseling concerning the recurrence risk in offspring will likely increase. This review presents the advancements in MRKH syndrome genetics from early familial occurrences and candidate gene searches to current genomic studies. Moreover, the review provides suggestions for future genetic investigations and discusses potential implications for clinical practice.

TP63 truncating mutation causes increased cell apoptosis and premature ovarian insufficiency by enhanced transcriptional activation of CLCA2

BACKGROUND

Premature ovarian insufficiency (POI) is a severe disorder leading to female infertility. Genetic mutations are important factors causing POI. TP63-truncating mutation has been reported to cause POI by increasing germ cell apoptosis, however what factors mediate this apoptosis remains unclear.

METHODS

Ninety-three patients with POI were recruited from Beijing Obstetrics and Gynecology Hospital, Capital Medical University. Whole-exome sequencing (WES) was performed for each patient. Sanger sequencing was used to confirm potential causative genetic variants. A minigene assay was performed to determine splicing effects of TP63 variants. A TP63-truncating plasmid was constructed. Real-time quantitative PCR, western blot analyses, dual luciferase reporter assays, immunofluorescence staining, and cell apoptosis assays were used to study the underlying mechanism of a TP63-truncating mutation causing POI.

RESULTS

By WES of 93 sporadic patients with POI, we found a 14-bp deletion covering the splice site in the TP63 gene. A minigene assay demonstrated that the 14-bp deletion variant led to exon 13 skipping during TP63 mRNA splicing, resulting in the generation of a truncated TP63 protein (TP63-mut). Overexpression of TP63-mut accelerated cell apoptosis. Mechanistically, the TP63-mut protein could bind to the promoter region of CLCA2 and activate the transcription of CLCA2 several times compared to that of the TP63 wild-type protein. Silencing CLCA2 using a specific small interfering RNA (siRNA) or inhibiting the Ataxia Telangiectasia Mutated (ATM) pathway using the KU55933 inhibitor attenuated cell apoptosis caused by TP63-mut protein expression.

CONCLUSION

Our findings revealed a crucial role for CLCA2 in mediating apoptosis in POI pathogenesis, and suggested that CLCA2 is a potential therapeutic target for POI.

Implication of androgen receptor gene dysfunction in human Müllerian duct anomalies

BACKGROUND

Müllerian duct anomalies (MDAs) are congenital developmental disorders exhibiting as a variety of malformations of female reproductive tract. The identified etiology of MDAs is limited. The present study aimed to unravel the underlying genetic causes of MDAs.

METHODS

Rare variants in androgen receptor (AR) were called from the cohort consists of patients with MDAs and underwent whole exome sequencing (WES) at Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing, China. Sanger sequencing was used to confirm the causative genetic mutations. In silico analysis were used to classify the pathogenicity of each variant. Molecular modeling and simulations were conducted to investigate the conformational changes between the wild-type (WT) and mutant proteins.

RESULTS

A total of 3 rare heterozygous variants in AR from the MDAs cohort in our institution were identified, with unknown effects. All variants were missense mutations, including c.173A > T, c.558C > A and c.1208C > T, and were absent or rare in East Asian populations in Genome Aggregation Database and the Exome Aggregation Consortium Database. According to the American College of Medical Genetics and Genomics guidelines, c.1208C > T variant was classified as likely pathogenic, while the other two were variants of uncertain significance. During molecular dynamics simulations, WT and mutant proteins all reached stable status according to root-mean-square variance. Values of radius of gyration showed that Q58L and S186R protein would be more compact than WT, while the structure of A403V became looser. Despite, in comparison with WT, the number of hydrogen bonds increased in Q58L, while decreased in the other two variants. Furthermore, the solvent-accessible surface area diminished in Q58L and A403V while enlarged in S186R proteins, when compared with WT.

CONCLUSIONS

To our knowledge, this is the first report regarding the association of AR mutation and MDAs. The identification of these variants, predicted to damage the structure and function of AR protein, not only expanded the mutational spectrum of causative genes of MDAs, but provide novel molecular genetic reference for future studies.

Managing pronounced hematocolpos in Herlyn-Werner-Wunderlich syndrome: A comprehensive case report

Herlyn-Werner-Wunderlich (HWW) syndrome is a rare and complex congenital anomaly of the genitourinary system characterized by uterus didelphys, an obstructed hemivagina, and ipsilateral renal agenesis. It is the result of the maldevelopment of both the Mullerian and Wolffian ducts. Clinical manifestations of dysmenorrhea, dysuria, and urinary retention appear after menarche due to the accumulation of menstrual blood and distention of the obstructed hemivagina. Diagnosis of this anomaly is often delayed, and the obstructive nature of the condition is missed due to cyclic menstruation from the one canalized hemivagina. This case report represents a typical form of HWW syndrome to highlight the importance of considering this rare entity in an adolescent girl presenting with signs of dysmenorrhea and urinary complaints. A 13-year-old patient was presented at the obstetrics and gynecology clinic due to low abdominal pain and urinary retention on the fifth day of menstruation. For the last 6 months, the patient suffered progressive cyclic low abdominal pain associated with menstruation. Inspection of the external genitalia was unremarkable, and the hymenal membrane had a normal oval opening. An ultrasound examination revealed the sonographic features of the didelphys uterus and was suggestive of a right obstructed hemivagina with hematocolpos. Magnetic resonance imaging and computed tomography urography showed evidence of didelphys uterus, right blind obstructed hemivagina associated with huge hematocolpos, and ipsilateral renal agenesis. The diagnosis of HWW syndrome was established. Surgical resection of the vaginal septum was undertaken without delay, and the patient was discharged the following days.

Anatomical variations, treatment and outcomes of Herlyn-Werner-Wunderlich syndrome: a literature review of 1673 cases

PURPOSE

This study aimed to perform a systematic review of patients with Herlyn-Werner-Wunderlich syndrome (HWWS) and present the prevalence of symptoms, anatomical variants, endometriosis, surgical interventions, and short- and long-term outcomes.

METHODS

A structured search was performed in PubMed, Scopus, Embase, and China National Knowledge Infrastructure, and studies published between 1 January, 2000 and 19 April, 2022 were included. The following data on HWWS were recorded: symptoms, anatomical variations, surgical interventions and short- and long-term outcomes.

RESULTS

A total of 1673 patients were included in our analysis. The main symptoms were dysmenorrhea (53.8%), abnormal uterine bleeding (28.9%), and vaginal discharge (26.6%). The principal anomalies were right-obstructed hemivagina (57.3%), haematocolpos (81.7%), uterus didelphys (88.8%), and ipsilateral renal agenesis (93.1%). A majority of patients belonged to classification 1.1 (46.7%), with a blind hemivagina, and classification 2.1 (39.2%), with a small communication between two vaginas. The mainstay of treatment was vaginal septum excision (91.8%). Minimally invasive surgery (48.5%) was performed only after vaginal surgery (61.9%), and only a few patients required a second surgery (2.2%). Endometriosis was found in 9.6% of the patients. Fifty-two percent of them had ipsilateral ovarian endometriosis cysts. Pregnancy rate of these patients was 72.1%. The rate of adverse pregnancy outcomes was 22.4%. The caesarean section rate was 61.2%.

CONCLUSIONS

Patients with HWWS presented with nonspecific symptoms and demonstrated various combinations of anomalies. The most common anatomical variants are classifications 1.1 and 2.1. Vaginal septum excision is effective in relieving symptoms and preventing complications, with hysteroscopic surgery as an option where there is concern about protecting the hymen from minor injury. The pregnancy rate for these patients after surgery was satisfactory, and the rate of adverse pregnancy outcomes after surgery was acceptable. We advise females with urological anomalies to be screened for Müllerian anomalies because of the close association between these two types of anomalies. Thus, HWWS contributes to the occurrence of endometriosis; however, more research is required to investigate the relationship between pelvic endometriosis and HWWS.

Renal agenesis: A meta-analysis of its prevalence and clinical characteristics based on 15 641 184 patients

Our objective was to analyse the newest relevant data on worldwide prevalence and associated symptoms of renal agenesis (RA). This meta-analysis builds on previous systematic reviews to include bilateral RA, its symptoms and data on gender, unilateral RA and anomaly location prevalence. Review of available data included records in English and other languages from PubMed, Embase, ScienceDirect, Web of Science, SciELO, BIOSIS, Current Content Connect Korean Journal Database and Russian Citation Index and Google. A total of 15 641 184 patients were analysed in relation to the prevalence of RA. The pooled prevalence of RA was 0.03% (95% CI: 0.03%-0.04%). Based on 500 subjects, a pooled prevalence of 47.96% (95% CI: 31.55%-64.58%) for unilateral and 52.04% (95% CI: 35.42%-68.45%) for bilateral RA has been set. Our study presents the newest generalized findings on bilateral RA. There appears to be universal disease and symptom prevalence with minor differences between world regions, although quality of future observational research should include genomic data. This will provide even further insight into the prognosis of various renal anomalies and their etiologies.

MRI presentations of Müllerian duct anomalies in association with unilateral renal agenesis

AIM

To evaluate the presentations of Müllerian duct anomalies (MDAs) associated with unilateral renal agenesis (URA) on magnetic resonance imaging (MRI).

MATERIALS AND METHODS

From 2014 to 2021, 92 patients with MDAs coexisting with URA who had undergone MRI were reviewed, and imaging patterns were analysed.

RESULTS

Based on the different imaging patterns, there were 74 cases of Herlyn-Werner-Wunderlich (HWW) syndrome (80.4%), nine cases of unicornuate uterus (10.9%), and nine cases of Mayer-Rokitansky-Kuster-Hauser (MRKH) syndrome (8.7%). In HWW syndrome, URA was ipsilateral to the vaginal or cervical obstruction. All the nine cases of unicornuate uterus were obstructive, and the most common subtype was unicornuate uterus with a non-communicating functioning rudimentary horn. The other two cases of unicornuate uterus with no rudimentary horn were obstructed due to cervical os obliteration, one of which was complicated with contralateral absent ovary. URA was contralateral to the unicornuate uterus in all cases. In MRKH syndrome, seven patients had bilateral rudiments and ovaries, all of which were unilaterally or bilaterally located above the pelvic brim, and URA was ipsilateral to the ectopic ovary in all cases. The other two patients had unilateral absent rudiment, ovary, and ipsilateral URA.

CONCLUSIONS

MRI presentations of URA-associated MDAs are diverse, with HWW syndrome being the most common form, followed by different patterns of unicornuate uterus and MRKH syndrome. An ectopic or absent ovary might be associated with URA in MRKH syndrome and unicornuate uterus.

A novel combination of OHVIRA syndrome and likely causal variant in UMOD gene

OHVIRA syndrome (or Herlyn-Werner-Wunderlich syndrome) is a rare condition, consisting classically of obstructed hemi-vagina with ipsilateral renal agenesis. It may be associated with complex uterine malformations and more rarely with lower urinary tract anomalies. The contralateral kidney usually has normal function. A genetic etiology of this syndrome has not yet been confirmed. We report a patient who was diagnosed to have unilateral renal agenesis in early childhood, and then presented after menarche with features of OHVIRA syndrome. The contralateral kidney was relatively small and echogenic, and serum creatinine and uric acid were raised. A likely causal variant of the UMOD gene was detected on whole exome sequencing. Genetic studies in more patients with OHVIRA syndrome may elucidate further, whether the association with UMOD gene is causal in nature.

Variants in genes related to development of the urinary system are associated with Mayer-Rokitansky-Küster-Hauser syndrome

Mayer–Rokitansky–Küster–Hauser (MRKH) syndrome, also known as Müllerian agenesis, is characterized by uterovaginal aplasia in an otherwise phenotypically normal female with a normal 46,XX karyotype. Previous studies have associated sequence variants of PAX8, TBX6, GEN1, WNT4, WNT9B, BMP4, BMP7, HOXA10, EMX2, LHX1, GREB1L, LAMC1, and other genes with MRKH syndrome. The purpose of this study was to identify the novel genetic causes of MRKH syndrome. Ten patients with MRKH syndrome were recruited at Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing, China. Whole-exome sequencing was performed for each patient. Sanger sequencing confirmed the potential causative genetic variants in each patient. In silico analysis and American College of Medical Genetics and Genomics (ACMG) guidelines helped to classify the pathogenicity of each variant. The Robetta online protein structure prediction tool determined whether the variants affected protein structures. Eleven variants were identified in 90% (9/10) of the patients and were considered a molecular genetic diagnosis of MRKH syndrome. These 11 variants were related to nine genes: TBC1D1, KMT2D, HOXD3, DLG5, GLI3, HIRA, GATA3, LIFR, and CLIP1. Sequence variants of TBC1D1 were found in two unrelated patients. All variants were heterozygous. These changes included one frameshift variant, one stop-codon variant, and nine missense variants. All identified variants were absent or rare in gnomAD East Asian populations. Two of the 11 variants (18.2%) were classified as pathogenic according to the ACMG guidelines, and the remaining nine (81.8%) were classified as variants of uncertain significance. Robetta online protein structure prediction analysis suggested that missense variants in TBC1D1 (p.E357Q), HOXD3 (p.P192R), and GLI3 (p.L299V) proteins caused significant structural changes compared to those in wild-type proteins, which in turn may lead to changes in protein function. This study identified many novel genes, especially TBC1D1, related to the pathogenesis of MRKH syndrome. The identification of these variants provides new insights into the etiology of MRKH syndrome and a new molecular genetic reference for the development of the reproductive tract.