TMEM132A regulates mouse hindgut morphogenesis and caudal development.

Caudal developmental defects, including caudal regression, caudal dysgenesis and sirenomelia, are devastating conditions affecting the skeletal, nervous, digestive, reproductive and excretory systems. Defects in mesodermal migration and blood supply to the caudal region have been identified as possible causes of caudal developmental defects, but neither satisfactorily explains the structural malformations in all three germ layers. Here, we describe caudal developmental defects in transmembrane protein 132a (Tmem132a) mutant mice, including skeletal, posterior neural tube closure, genitourinary tract and hindgut defects. We show that, in Tmem132a mutant embryos, visceral endoderm fails to be excluded from the medial region of early hindgut, leading directly to the loss or malformation of cloaca-derived genitourinary and gastrointestinal structures, and indirectly to the neural tube and kidney/ureter defects. We find that TMEM132A mediates intercellular interaction, and physically interacts with planar cell polarity (PCP) regulators CELSR1 and FZD6. Genetically, Tmem132a regulates neural tube closure synergistically with another PCP regulator Vangl2. In summary, we have identified Tmem132a as a new regulator of PCP, and hindgut malformation as the underlying cause of developmental defects in multiple caudal structures.

T2-based magnetic resonance genitography in children with complex anorectal malformations: experience at a tertiary pediatric hospital in Latin America.

In children with anorectal malformations (ARMs), it is essential to have a diagnostic imaging method that helps with the evaluation of the internal anatomy. In patients with a persistent cloaca, an ARM variant, in which the measurement of the urethral channel and common channel determines surgical management, there are multiple options for imaging. Magnetic resonance imaging (MRI) is an excellent method for this purpose, from which accurate measurements of channel length can be obtained. Additionally, the use of volumetric/isotropic sequences allows multiplanar reformatting. We present our experience with pelvic MRI and intracavitary non-paramagnetic contrast (MR genitography). This method uses volumetric T2-weighted images and the instillation of saline solution as a contrast agent to distinguish the common channel, length of the urethra, anatomy of the vagina, and presence and location of the rectal fistula. We believe this technique to be particularly useful for those working in settings with limited MRI resources.

The postoperative renal function of persistent cloaca patients treated by posterior sagittal anorecto-urethro-vaginopalsty: results of a nationwide survey in Japan.

PURPOSE: We investigated the postoperative renal function in persistent cloaca (PC) patients who underwent posterior sagittal anorecto-urethro-vaginopalsty (PSARUVP) and factors influencing the renal functional outcomes. METHODS: A questionnaire survey was distributed to 244 university and children's hospitals across Japan. Of the 169 patients underwent PSARUVP, 103 patients were enrolled in the present study. Exclusion criteria was patients without data of renal prognosis. RESULTS: The present study showed that renal anomalies (p = 0.09), vesicoureteral reflux (VUR) (p = 0.01), and hydrocolpos (p = 0.07) were potential factors influencing a decline in the renal function. Approximately half of the patients had a normal kidney function, but 45.6% had a reduced renal function (Stage ≥ 2 chronic kidney disease: CKD). The incidence of VUR was significantly higher in the renal function decline (RFD) group than those in the preservation (RFP) group (p = 0.01). Vesicostomy was significantly more frequent in the RFD group than in the RFP group (p = 0.04). Urinary tract infections (p < 0.01) and bladder dysfunction (p = 0.04) were significantly more common in patients with VUR than in patients without VUR. There was no association between the VUR status and the bowel function. CONCLUSIONS: Prompt assessment and treatment of VUR along with bladder management may minimize the decline in the renal function.

Urological outcomes in adult females born with anorectal malformation or Hirschsprung disease.

INTRODUCTION: Women born with anorectal malformation (ARM) or Hirschsprung disease (HD) may have impaired urologic function resulting in sequelae in adulthood. This study assessed and compared self-reported urinary outcomes in adult females born with ARM or HD to a reference population. METHODS: This was an IRB approved, cross-sectional study of female-born patients with ARM or HD, who completed surveys between November 2021 and August 2022. Female patients between the ages of 18 and 80 years were included. Lower Urinary Tract Symptom Questionnaires were administered through REDCap and the responses were compared to a reference population using Chi-squared or Fisher's exact tests. RESULTS: Sixty-six born female patients answered the questionnaires, two of them identified as non-binary. The response rate was 76%. Median age was 31.6 years. The majority were born with cloaca (56.3%), followed by other type of ARMs (28.1%), complex malformation (9.4%), and HD (6.3%). A history of bladder reconstruction was present for 26.6%. Catheterization through a channel or native urethra was present in 18.8%. Two had ureterostomies and were excluded from the analysis. Seven had chronic kidney disease or end-stage renal disease, three with a history of kidney transplantation. Patients with cloaca had significantly higher rates of urinary incontinence, urinary tract infection, and social problems due to impaired urological functioning, when compared to an age-matched reference population (Table 3). CONCLUSION: This study emphasizes the need for a multi-disciplinary team that includes urology and nephrology following patients with ARM long term, especially within the subgroup of cloaca. LEVEL OF EVIDENCE: III.

Qualitative inductive analysis of the lives of women with persistent cloaca based on their narratives.

PURPOSE: The study aimed to explore and describe the lives of patients with persistent cloaca (PC) from childhood to adulthood. METHODS: Semistructured interviews were conducted with nine adult patients with PC. Their experiences and thoughts regarding this disease were analyzed qualitatively and inductively. RESULTS: After classifying the experiences and thoughts of patients with PC, 13 categories were extracted. The following five themes emerged from these categories. (1) Difficulties with excretion and vaginal management because of the disease. (2) The degree of understanding of those around them and society has a huge effect on their way of life. (3) The inferiority of a woman who is not a "normal woman." (4) A "never-ending disease" in which problems continue even after the transition period. (5) Differences in the central point of the narrative depending on the age group. CONCLUSIONS: In this study, qualitative and inductive analyses of data from semistructured interviews with patients with PC revealed their experiences and thoughts. The results will provide a guide for young patients and the medical professionals who treat them. Accordingly, monitoring their lives until adulthood is necessary.

Endoscopy and rectal enema for fecal collection in wild sea turtles (Chelonia mydas, Eretmochelys imbricata) in a field setting.

Forty-seven free-ranging sea turtles (46- Chelonia mydas, 1- Eretmochelys imbricata) were examined via novel use of an endoscopy combined with a rectal enema to obtain large fecal sample volumes. The cloaca was insufflated using an endoscope, after which the bladder and rectum separated, allowing access to the colon. Environmental conditions and location influenced the performance of the procedure initially, but after several attempts the procedure was successfully initiated. In all cases, fecal samples were obtained, and the animals were released to their respective locations. Fecal sample collection using this approach enhances the ability to obtain diagnostic information and perform other scientific analyses of sea turtles.

Persistent Cloaca and Cloacal Variants in Males: Qualitative Review of a Neglected Anomaly.

Context: Cloacal malformations are rare and are typically reported in females. There are a few scattered reports in males. It is not clear why they are so rare in males since both sexes negotiate this stage of embryonal development. Aims: The present study aims to share our experience and review all the cases of persistent cloaca and cloacal variants in males reported in the literature. Materials and Methods: The male cloaca is defined as a single common channel of varying lengths with separate inlets for the urinary tract (urethra) anteriorly and the rectum posteriorly at its cranial end and with a solitary perineal orifice/opening for external drainage. We also carried out an electronic literature search for cloaca, persistent cloaca, common cloaca, cloacal dysgenesis, cloacal malformation, cloacal membrane agenesis, urorectal malformation sequence, rectourinary perineal fistula, sirenomelia, and caudal regression syndrome. Results: After eliminating other cloacal anomalies and persistent cloaca in females, we found a total of 22 males with persistent cloaca or cloacal variant reported in the literature. In addition, we are adding two cases we have managed since our previous report. Conclusions: An effort should be made to search for the presence of the common channel in male patients with a single perineal opening. Recognition of the anomaly, width of the common cloacal channel, location of the rectal pouch with relation to the sacrum or pubis, status of the spine and sacrum, and nature of the anal sphincter are vital pieces of information to successfully manage the anomaly. It would be worthwhile if future reports on the subject also include long-term information about urinary and fecal functions and continence.

Inversin (NPHP2) and Vangl2 are required for normal zebrafish cloaca formation.

Nephronophthisis (NPH), an autosomal recessive ciliopathy, results from mutations in more than 20 different genes (NPHPs). These gene products form protein complexes that regulate trafficking within the cilium, a microtubular structure that plays a crucial role in developmental processes. Several NPHPs, including NPHP2/Inversin, have been linked to extraciliary functions. In addition to defining a specific segment of primary cilia (Inversin compartment), NPHP2 participates in planar cell polarity (PCP) signaling along with Dishevelled and Vangl family members. We used the mutant zebrafish line invssa36157, containing a stop codon at amino acid 314, to characterize tissue-specific functions of zebrafish Nphp2. The invssa36157 line exhibits mild ciliopathy phenotypes and increased glomerular and cloaca cyst formation. These mutants showed enhanced susceptibility to the simultaneous depletion of the nphp1/nphp2/nphp8 module, known to be involved in the cytoskeletal organization of epithelial cells. Notably, simultaneous depletion of zebrafish nphp1 and vangl2 led to a pronounced increase in cloaca malformations in the invssa36157 mutant embryos. Time-lapse imaging showed that the pronephric cells correctly migrated towards the ectodermal cells in these embryos, but failed to form the cloaca opening. Despite these abnormal developments, cellular fate does not seem to be affected in nphp1 and vangl2 MO-depleted invssa36157 mutants, as shown by in situ hybridizations for markers of pronephros and ectodermal cell development. However, significantly reduced apoptotic activity was observed in this double knockdown model, signifying the role of apoptosis in cloacal morphogenesis. Our findings underscore the critical interplay of nphp1, nphp2/Inversin, and vangl2 in orchestrating normal cloaca formation in zebrafish, shedding light on the complex molecular mechanisms underlying ciliopathy-associated phenotypes.

The role of p63 in embryonic external genitalia outgrowth in mice.

Embryonic external genitalia (genital tubercle [GT]) protrude from the cloaca and outgrow as cloacal development progresses. Individual gene functions and knockout phenotypes in GT development have been extensively analyzed; however, the interactions between these genes are not fully understood. In this study, we investigated the role of p63, focusing on its interaction with the Shh-Wnt/Ctnnb1-Fgf8 pathway, a signaling network that is known to play a role in GT outgrowth. p63 was expressed in the epithelial tissues of the GT at E11.5, and the distal tip of the GT predominantly expressed the ΔNp63α isoform. The GTs in p63 knockout embryos had normal Shh expression, but CTNNB1 protein and Fgf8 gene expression in the distal urethral epithelium was decreased or lost. Constitutive expression of CTNNB1 in p63-null embryos restored Fgf8 expression, accompanied by small bud structure development; however, such bud structures could not be maintained by E13.5, at which point mutant GTs exhibited severe abnormalities showing a split shape with a hemorrhagic cloaca. Therefore, p63 is a key component of the signaling pathway that triggers Fgf8 expression in the distal urethral epithelium and contributes to GT outgrowth by ensuring the structural integrity of the cloacal epithelia. Altogether, we propose that p63 plays an essential role in the signaling network for the development of external genitalia.

Clinically diverse and perinatally lethal syndromes with urorectal septum malformation sequence.

Urorectal septum malformation sequence (URSMS) is characterized by a spectrum of anomalies of the urogenital system, hindgut and perineum. It is presumed to be a constellation of an embryonic defect. Herein, we analyzed the clinically diverse syndromes associated with URSMS in our perinatal evaluation unit. We reviewed fetuses with URSMS in referrals for perinatal autopsy over a period of 3 years. Chromosomal microarray and genome sequencing were performed whenever feasible. Literature was reviewed for syndromes or malformations with URSMS. We ascertained URSMS in 12 of the 215 (5%) fetuses. Nine fetuses (75%) had complete URSMS and remainder had partial/intermediate URSMS. Eleven fetuses had malformations of other systems that included: cerebral ventriculomegaly; right aortic arch with double outlet right ventricle; microcephaly with fetal akinesia deformation sequence; ventricular septal defect and radial ray anomaly; thoraco-abdominoschisis and limb defects; myelomeningocele; spina bifida and fused iliac bones; omphalocele; occipital encephalocele; lower limb amelia and cleft foot. We report on six fetuses with recurrent and five fetuses with unique malformations/patterns where URSMS is a component. Exome sequencing (one family) and genome sequencing (eight families) were performed and were nondiagnostic. Additionally, we review the literature for genetic basis of this condition. URMS is a clinically heterogeneous condition and is a component of several multiple malformation syndromes. We describe several unique and recurrent malformations associated with URSMS.

Outcome after vaginal delivery of women with a previous medical history of surgically corrected anorectal malformations: a systematic review.

OBJECTIVE: Discussion remains on how to advise women with a past medical history of surgically corrected anorectal malformations (ARMs) regarding vaginal delivery. The aim of this review is to evaluate and review the reported obstetrical complications and outcomes after vaginal delivery for these women. DATA SOURCES: A systematic search was performed from inception up to 25 July 2022 in PubMed, Embase.com and Clarivate Analytics/Web of Science Core Collection, with backward citation tracking. STUDY ELIGIBILITY CRITERIA/APPRAISAL: All articles reported on the outcomes of interest in women with a past medical history of surgically corrected anorectal malformation and had a vaginal delivery were included with the exception of editorial comments or invitational commentaries. Screening, data extraction and risk of bias assessment was done by two authors independently with a third and fourth reviewer in case of disagreement. Tool for Quality assessment depended on the type of article. As low quality evidence was expected no meta-analysis was performed. RESULTS: Only five of the 2377 articles screened were eligible for inclusion with a total of 13 attempted vaginal deliveries in eight women. In three patients complications were reported: failed vaginal delivery requiring urgent cesarean section in two patients, and vaginal tearing in one patient. CONCLUSION: High quality evidence regarding outcomes and complications after vaginal delivery in women with a history of surgically corrected anorectal malformation is lacking. Therefore, based upon this systematic review no formal recommendation can be formulated regarding its safety. Future studies are essential to address this problem. TRIAL REGISTRATION: CRD42020201390. Date: 28-07-2020s.

Fetal ascites in cloacal malformations-a red flag.

INTRODUCTION: Cloacal malformation is a rare anomaly that remains a diagnostic challenge prenatally, despite the current advances in ultrasonography and MRI. This condition can in some, present with isolated ascites or with other findings, such as a pelvic cyst or upper urinary tract dilatation. In a minority, the ascites may be progressive, questioning the role of antenatal intervention. METHODS: We report on ten patients that have been identified from our Cloaca database between 2010 and 2022. RESULTS: The presence of ascites was associated with extensive bowel adhesions and matting, leading to a challenging initial laparotomy and peri-operative course. CONCLUSIONS: Antenatal finding of ascites in newborns with cloacal malformations should raise a red flag. The surgeon and anaesthetist should be prepared for the operative difficulties secondary to bowel adhesions and the higher risk of haemodynamic instability at the initial surgery. An experienced team at initial laparotomy in such patients is vital. LEVEL OF EVIDENCE: II.

Posterior sagittal anorecto-urethro-vagino-plasty in the late period was associated with the long-term bowel function in patients with persistent cloaca: results of a nationwide survey in Japan.

PURPOSE: After conducting a nationwide survey of persistent cloaca (PC), we assessed whether or not the timing of definitive anorectoplasty affects the long-term bowel function of patients with PC. METHODS: Patient information was obtained via questionnaire, and a total of 169 PC patients who underwent posterior sagittal anorectourethrovaginoplasty (PSARUVP) were enrolled in this study. Patients were classified into 2 groups based on their operative period, which was analyzed by the area under the receiver operating characteristic curve: the early group (EG) underwent anorectoplasty at ≤ 18 months old (n = 106), and the late group (LG) underwent anorectoplasty at > 18 months old (n = 63). The bowel function was evaluated using the evacuation score of the Japan Society of Anorectal Malformation Study Group. We also examined the postoperative results of vaginoplasty. RESULTS: The total evacuation score was significantly higher in the EG than in the LG (5.2 ± 1.7 vs. 4.2 ± 1.8, p = 0.003). The frequency of bowel movement and the constipation scores were significantly higher in the EG than in the LG (1.4 ± 0.6 vs. 1.2 ± 0.7, p < 0.05, 2.4 ± 1.0 vs. 2.1 ± 1.0, p < 0.05, respectively). Postoperative vaginal stenosis was observed in 18 cases (10.7%), of which 16 could be reconstructed transperineally. CONCLUSION: PSARUVP should be performed in early infancy and facilitate vaginal reconstruction.

Fertility concerns and outcomes in females with anorectal malformations.

PURPOSE: To assess fertility concerns and to describe pregnancy outcomes in patients with anorectal malformations (ARM). METHODS: This is an IRB approved, cross-sectional study of patients in the Adult Colorectal Research Registry who completed reproductive health surveys between November 2021 and August 2022. Patients assigned female at birth with age 18 or older and ARM were included. RESULTS: Sixty-four patients with ARM, age 18 or older, were included. Fertility concerns were reported in 26 (40.6%) patients, 11 of which had seen a fertility specialist, including four who had not yet tried to conceive. Fertility concerns were highest amongst cloaca patients who had not yet tried to conceive (37.5%). 26 (40.6%) patients had tried to conceive, of which 16 (25%) reported fertility problems, most frequently uterine abnormalities and damaged or blocked fallopian tubes. 22 (34.4%) participants were able to conceive and 18 (28.1%) had at least one live birth. Patients with ARM who had concerns of fertility, had better FertiQoL when compared to published reference scores for patients experiencing fertility issues. CONCLUSION: Providers should be aware of fertility concerns in patients with ARM. Proactive counseling with referrals to a fertility specialist should be considered in patients who desire future fertility.

Analysis of the potential risk factors for defecation problems and their bowel management based on the long-term bowel function in patients with persistent cloaca: results of a nationwide survey in Japan.

AIM OF THE STUDY: We conducted a nationwide survey of persistent cloaca (PC) to determine its current status in Japan. This study clarifies the potential risk factors for defecation problems in patients with PC. METHODS: Patient information was obtained via questionnaire, and a total of 213 PC patients who responded to a questionnaire on defecation problems and their bowel functions were enrolled in this study. We evaluated the constipation, incontinence, and soiling as bowel functions. Univariate and multivariate analyses were performed using a logistic regression analysis to clarify the risk factors for defecation problems. RESULTS: Of 213 patients with PC, 55 (25.8%) had defecation problems. A multivariate logistic regression analysis showed that sacral agenesis, as an associated anomaly, was significantly associated with defecation problems (odds ratio [OR] 3.19, 95% confidence interval [CI] 1.11-9.16, p = 0.03). The other multivariate logistic regression analysis showed that the PC patients who underwent antegrade continence enema and regularly took laxatives after anorectoplasty had defecation problems (OR 12.4, 95% CI 2.35-65.6, p = 0.003, OR 2.84, 95% CI 1.24-6.55, p = 0.01). CONCLUSION: Sacral agenesis is the potential risk factor of defecation problems in the patients with PC who underwent anorectoplasty. Those patients require vigorous defecation management.

Long-term urological outcome of cloaca patients with multidisciplinary management.

PURPOSE: Urological management of Cloacal Malformation (CM) focuses on preserving renal function and continence. Study aim was to analyze urinary and intestinal outcomes in CM patients, considering the length of common channel (CC) and presence of occult spinal dysraphism (OSD). METHODS: Retrospective review of CM treated at our institution by a multidisciplinary team from 1999 to 2020. Patients with follow-up < 2.5 years were excluded. Length of CC, renal function, urinary and bowel outcomes, presence of associated anomalies (especially OSD) were evaluated. RESULTS: Twenty patients were included, median age at follow-up: 8 years (4-15). A long CC > 3 cm was described in 11 (55%). Chronic kidney disease was found in 3 patients. Urinary continence was achieved in 8/20 patients, dryness (with intermittent catheterization) in 9/20. Fecal continence was obtained in 3/20, cleanliness in 14 (under bowel regimen). OSD was present in 10 patients (higher prevalence in long-CC, 73%). Among OSD, 1 patient reached fecal continence, 7 were clean; 2 achieved urinary continence, while 6 were dry. CONCLUSIONS: Length of CC and OSD may affect urinary and fecal continence. An early counseling can improve outcome at long-term follow-up. Multidisciplinary management with patient centralization in high grade institutions is recommended to achieve better results.

Prenatal Rupture of Hydrocolpos in a Cloacal Malformation.

INTRODUCTION: Cloacal dysgenesis occurs from failure of embryological division of urogenital sinus and hindgut, leading to a single common perineal opening for genitourinary and gastrointestinal tracts. The prenatal diagnosis of cloacal malformation is imprecise, but the clinical correlation of postnatal findings to prenatal history can help reveal explanations for unusual pathological findings in patients with urogenital abnormalities. CASE PRESENTATION: A 21-year-old woman was referred after her 20-week ultrasound demonstrated anhydramnios and concern for dilated fetal bowel. Fetal MRI confirmed anhydramnios and a dilated fetal colon, in addition to hydronephrosis and a pelvic cyst. Repeat ultrasound at 27 weeks showed unexpected complete resolution of her anhydramnios but new fetal ascites. The newborn girl was postnatally diagnosed with a cloacal malformation and an unusual near-complete fusion of her labia. She underwent proximal sigmoid colostomy and a tube vaginostomy at birth followed by cloacal reconstruction at 1.5 years old. CONCLUSION: In female fetus with a pelvic cyst, one should have a high index of suspicion for cloacal anomaly and consider the possibility of urinary obstruction leading to alteration in amniotic fluid.

Sex identification in Australian skinks (Egernia stokesii, E. hosmeri, E. striolata) using cloacoscopy.

Thirteen adult healthy captive skinks, six Gidgee spiny-tailed skinks (Egernia stokesii), three Hosmer's spiny-tailed skinks (Egernia hosmeri) and four tree crevice-skinks (Egernia striolata), were submitted to the study. The weight of the animals ranged from 28 g to 146 g. All skinks were explored during their putative mating season, which is December. Lizards were restrained manually and positioned in ventral recumbence. Cloacoscopy was performed with the rigid endoscope, protecting channel, endocamera and recording system Telepack-Pal (Karl Storz Endoskope, Tuttlingen, Germany). While the endoscope was gently introduced into the cloaca and advanced into the coprodeum sterile saline was flushed into the cloaca through the protecting channel. The endoscope was then slowly withdrawn to allow visualization of the main structures of the urodeum and proctodeum. Male skinks are characterized by the presence of urethral papillae and only one horizontal septum which divides the chamber of the urodeum into two subchambers. Female skinks are characterised by the presence of two septa. The central-dorsal fold that divides the urodeum into two pouches in female skinks is absent in males. Cloacoscopy proved an effective method of sex identification and can be considered a valuable method for breeding and conservation in monomorphic skink lizards.

The broader phenotypic spectrum of congenital caudal abnormalities associated with mutations in the caudal type homeobox 2 gene.

The caudal type homeobox 2 (CDX2) gene encodes a developmental regulator involved in caudal body patterning. Only three pathogenic variants in human CDX2 have been described, in patients with persistent cloaca, sirenomelia and/or renal and anogenital malformations. We identified five patients with de novo or inherited pathogenic variants in CDX2 with clinical phenotypes that partially overlap with previous cases, that is, imperforate anus and renal, urogenital and limb abnormalities. However, additional clinical features were seen including vertebral agenesis and we describe considerable phenotypic variability, even in unrelated patients with the same recurrent p.(Arg237His) variant. We propose CDX2 variants as rare genetic cause for a multiple congenital anomaly syndrome that can include features of caudal regression syndrome and VACTERL. A causative role is further substantiated by the relationship between CDX2 and other proteins encoded by genes that were previously linked to caudal abnormalities in humans, for example, TBXT (sacral agenesis and other vertebral segmentation defects) and CDX1 (anorectal malformations). Our findings confirm the essential role of CDX2 in caudal morphogenesis and formation of cloacal derivatives in humans, which to date has only been well characterized in animals.

Divergent variant patterns among 19 patients with Rubinstein-Taybi syndrome uncovered by comprehensive genetic analysis including whole genome sequencing.

Rubinstein-Taybi syndrome (RSTS) is characterized by dysmorphic facial features, broad thumbs, and intellectual disability. CREB-binding protein (CREBBP) or E1A-binding protein P300 (EP300) are causative genes. To elucidate the underlying genetic and genomic architecture related to the RSTS phenotype, we performed comprehensive genetic analysis targeting CREBBP and/or EP300 in 22 clinically diagnosed patients. During the 11-year study period, we used several analysis methods including high-resolution melting, array-based comparative genomic hybridization, panel-based exome sequencing, whole exome sequencing, and whole genome sequencing (WGS). We identified the causative variants in 19 patients (86.3%), but they were variable and complex, so we must combine multiple analysis methods. Notably, we found genetic alterations in the non-coding regions of two patients (10.5%, 2/19): scattered deletions including a partial 5'-untranslated region of CREBBP in one patient (all coding exons were intact), and a deep 229-bp intronic deletion in another patient, resulting in a splicing error. Furthermore, we identified rare clinical findings: two patients with an EP300 variant showed abnormal development of the neural tube, and one patient with a CREBBP variant had anorectal atresia with a cloaca. Our findings expand the allelic heterogeneity of RSTS, underscore the utility of comprehensive genetic analysis, and suggest that WGS may be a practical diagnostic strategy.