The etiology of VACTERL association: Current knowledge and hypotheses

Outcomes of Management of Anterior Anus in Girls in Glasgow, UK

BACKGROUND

Anterior anus is considered part of the spectrum of anorectal malformations in girls and has been associated with childhood constipation. However, limited literature exists on outcomes and associated malformations.

METHODS

All girls <6 months referred to our centre with suspected anterior anus between January 2015 and December 2022 were identified. Data collected included patient demographics, presence of anomalies, operative management, laxative use and continence. Results are described using descriptive statistics and percentages.

RESULTS

147 girls were referred with suspected anterior anus of which 95 were confirmed to have an anterior anus. Median age of first assessment was 3 (0-13) months. Median follow up was 24 (1-94) months. 21 (22.1 %) had clinical concern of partial absence of normal circumferential anal corrugation. 10 (10.5%) girls underwent examination under anaesthesia; 4 patients underwent anoplasty with covering colostomy. Laxatives were prescribed in 31 (32.6%) girls. Of the 53 patients followed up to age 4 years and older, 51 (96.2%) achieved continence. On renal ultrasonography significant hydroureteronephrosis was detected in one patient. No significant spinal anomalies were detected on imaging. Two patients had ventricular-septal defects were identified. All significant anomalies were in patients with an ectopic anus/ perineal fistula.

CONCLUSION

This represents the largest reported series of girls with anterior anus. The incidence of identified associated malformations was low. Furthermore, laxative use and continence outcomes are similar to the general infant/childhood population. Screening and routine follow-up should be reserved for individual cases where there is clinical concern.

Persistent Urogenital Sinus Leading to Hydrometrocolpos in a Female Child With Features of McKusick-Kaufman Syndrome

Persistent urogenital sinus (PUGS) presents as a solitary abnormality or is in association with syndromes, such as congenital adrenal hyperplasia (CAH), VACTERL association (common abbreviation for vertebral defects, anal atresia, cardiac defects, tracheoesophageal fistula, renal anomalies, and limb abnormalities), Bardet-Beidl syndrome, McKusick-Kaufman syndrome (MKS), and Townes-Brocks syndrome, to name a few. Those affected usually have overlapping phenotypic features of two or more syndromes. Because such children may grow up to be intellectually challenged with multiple other anomalies including gonadal hyperplasia, congenital heart defects, and sensorineural hearing loss, antenatal diagnosis becomes important. Moreover, those who survive into childhood may need a holistic approach to improve their quality of life. This is a rare case of an eight-year-old female child who is a postnatally diagnosed case of congenital heart disease, urogenital sinus with polydactyly, and bilateral hydroureteronephrosis at birth and who is now showing features of multiple overlapping syndromes.

Transient hypogammaglobulinemia of infancy and unclassified syndromic immunodeficiencies are highly common in oesophageal atresia patients

Due to the high rate of post-operative sepsis and other infectious complications, a routine immunological screening protocol has been initiated since 2015 in our paediatric surgery clinic for all patients admitted with oesophageal atresia (EA) and warrant a delayed definitive treatment. In our study, we aimed to evaluate the immunodeficiencies in EA patients, by comparing them to healthy age-matched controls. As a prospective cohort study, EA patients admitted between 2015 and 2022, who had their definitive operation after the newborn period (>28 days of age) were included. On admission, serum concentrations of IgG, IgA, IgM, lymphocyte subset levels, C3 and C4 levels, specific IgG antibody responses against hepatitis B, hepatitis A, measles, varicella zoster were evaluated. The patients were age-matched with healthy controls to compare the results and followed up until three years of age. If a humoral immunodeficiency was detected, intravenous immunoglobulin treatment was administered before major oesophageal surgery and during follow-up. 31 EA patients (18 M/13F) with a mean age of 13.3 ± 9.0 months were compared with 40 age-matched healthy controls. Mean serum IgG levels were found to be statistically lower than controls in all age groups (P < .05). Transient hypogammaglobulinemia of infancy (THI) and unclassified syndromic immunodeficiencies (USI) were found to be strikingly high, accounting for 29.0% and 22.5%, respectively, adding up to 51.5% of EA patients. This is the first study evaluating immunodeficiencies in EA patients found in the reviewed literature. More than half of EA patients that required delayed surgery had humoral immunodeficiency, so preoperative screening and immunology referral may improve patient outcomes.

Ear anomalies and hearing loss in patients with VACTERL association and the effect of maternal diabetes

VACTERL association is typically defined as the presence of three components among these birth defects: vertebral anomalies, anal atresia, cardiac anomalies, esophageal atresia/tracheoesophageal fistula (EA/TEF), renal anomalies, and limb defects. There is increasing recognition that VACTERL and other recurrent constellations of embryonic development often overlap clinically and might share pathogenesis. We conducted a comprehensive chart review of a large patient population with VACTERL association from two tertiary care centers in California. We included patients with incomplete VACTERL expression, which we denoted as "partial VACTERL" (pVACTERL). We assessed the occurrence of craniofacial (CF) findings in these two groups and the combined cohort. We collected data on potential risk factors and demographic information such as sex, Hispanic ancestry, pregnancy complications, and maternal age. The study included 409 participants, of whom 263 had VACTERL and 146 pVACTERL. CF abnormalities were found in 17.3% of VACTERL patients and 9.4% of pVACTERL patients. In the VACTERL group, ear anomalies were found in 10.2%, microtia in 5.9%, hearing loss (HL) in 13.90%, and orofacial clefts in 3.1%. In the pVACTERL group, ear anomalies were found in 7.2%, microtia in 5.0%, HL in 9.3%, and orofacial cleft in 2.2%. Maternal diabetes significantly increased the risk for HL in VACTERL (odds ratio [OR]: 3.71, 95% confidence interval [CI]: 1.5-7.3) and pVACTERL patients (OR: 6.7, 95% CI: 1.70-23.4). Poorly controlled maternal diabetes significantly increased the risk for all the outcomes in VACTERL patients including CF anomalies (OR: 4.2, 95% CI: 1.9-9.6), ear anomalies (OR: 4.7, 95% CI: 1.8-11.8), microtia (OR: 5.4, 95% CI: 1.7-16.6), and HL (OR: 8.1, 95% CI: 3.4-19.4). Twin status was significantly associated with the occurrence of microtia (p = 0.038) in VACTERL patients. Occurrence of CF features, particularly ear anomalies, microtia, and HL, might be considered as part of phenotypic diversity of VACTERL association. Diabetes and twinning might appear to play a role in increasing the risk for this phenotype in VACTERL association.

Disorders of the central nervous system: Insights from Notch and Nrf2 signaling

The functional complexity of the central nervous system (CNS) is unparalleled in living organisms. It arises from neural crest-derived cells that migrate by the exact route, leading to the formation of a complex network of neurons and glial cells. Recent studies have shown that novel crosstalk exists between the Notch1 and Nrf2 pathways and is associated with many neurological diseases. The Notch1-Nrf2 axis may act on nervous system development, and the molecular mechanism has recently been reported. In this review, we summarize the essential structure and function of the CNS. The significance of interactions between signaling pathways and between developmental processes like proliferation, apoptosis and migration in ensuring the correct development of the CNS is also presented. We primarily focus on research concerning possible mechanism of interaction between Notch1 and Nrf2 and the functions of Notch1-Nrf2 in neurons. There may be a direct interaction between Notch1 and NRF2, which is closely related to the crosstalk that occurs between them. The significance and potential applications of the Notch1-Nrf2 axis in abnormal development of the nervous system are been highlighten. We also discuss the molecular mechanisms by which the Notch1-Nrf2 axis controls the apoptosis, antioxidant pathway and differentiation of neurons to modulate the development of the nervous system. This information will lead to a better understanding of Notch1-Nrf2 axis signaling pathways in the nervous system and may facilitate the development of new therapeutic strategies.

Craniofacial Microsomia, Associated Congenital Anomalies, and Risk Factors in 63 Cases from the Alberta Congenital Anomalies Surveillance System

OBJECTIVE

To report associated congenital anomalies with unexplained craniofacial microsomia (CFM) and the phenotypic overlap with other recurrent constellations of embryonic malformations (RCEM), and to assess prenatal and perinatal risk factors.

STUDY DESIGN

This is a retrospective cross-sectional study. Cases with CFM, delivered between January 1, 1997, and December 31, 2019, were abstracted from the population-based Alberta Congenital Anomalies Surveillance System. Livebirths, stillbirths, and early fetal losses were reviewed to include all types of pregnancy outcomes along the spectrum of this condition. Prenatal and perinatal risk factors were compared with the Alberta birth population to assess differences between the 2 groups.

RESULTS

There were 63 cases with CFM, yielding a frequency of 1 per 16 949. There was a high rate of cases (65%) with anomalies outside the craniofacial and vertebral regions. Congenital heart defects were the most common (33.3%). A single umbilical artery was found in 12.7% of cases. The twin/triplet rate of 12.7% was significantly higher than the Alberta rate of 3.3% (P < .0001). There was an overlap with a second RCEM condition in 9.5% of cases.

CONCLUSIONS

Although CFM is primarily a craniofacial condition, the majority of cases have congenital anomalies affecting other systems requiring additional assessments, including an echocardiogram, renal ultrasound examination, and a complete vertebral radiograph. The high rate of an associated single umbilical artery raises the possibility of a related etiological mechanism. Our findings support the proposed concept of RCEM conditions.

Fetal Tethered Spinal Cord: Diagnostic Features and Its Association with Congenital Anomalies

OBJECTIVE

We assessed the frequency and type of associated congenital anomalies encountered with fetal tethered spinal cord (TSC) determined prenatally.

METHOD

A retrospective review was conducted based on the associated fetal abnormalities following diagnosis of low-lying fetal conus medullaris during the prenatal ultrasound.

RESULTS

Of the 26 fetuses with low-lying conus medullaris, four were solitary TSC and 22 had TSC combined with associated congenital malformations, including four cases with spina bifida occulta, four cases with spina bifida aperta, one case with severe hydrocephalus, and 13 cases with multisystem congenital malformations. Among all the 13 cases with combined multisystem congenital malformations, four cases had vertebral defects, anal anomalies, cardiac defects, trachea-esophageal fistula, renal anomalies, and limb anomalies (VACTERL) syndrome, two cases had combined kidney development abnormalities, one case had cloacal exstrophy (OEIS syndrome), and six cases had chromosomal abnormalities (one case of chromosome 7q deletion, two cases of trisomy 13 syndrome, one case of trisomy 18 syndrome, one case of trisomy 9 syndrome, and one case of chromosome 4p deletion).

CONCLUSIONS

Low-lying conus medullaris found during prenatal ultrasound examination were often associated with neural tube malformations or multi-systemic complex developmental malformations. The frequency of chromosomal abnormalities was 23.1%.

Clinical Presentations and Diagnostic Imaging of VACTERL Association

Background: VACTERL association consists of Vertebral, Anorectal, Cardiac, Tracheo-Esophageal, Renal, and Limb defects. The diagnosis depends on the presence of at least three of these structural abnormalities. Methods: The clinical presentation and diagnostic prenatal imaging of VACTERL association are comprehensively reviewed. Results: The most common feature is a vertebral anomaly, found in 60-80% of cases. Tracheo-esophageal fistula is seen in 50-80% of cases and renal malformations in 30% of patients. Limb defects including thumb aplasia/hypoplasia, polydactyly, and radial agenesis/hypoplasia are present in 40-50% of cases. Anorectal defects, like imperforate anus/anal atresia, are challenging to detect prenatally. Conclusion: The diagnosis of VACTERL association mostly relies on imaging techniques such as ultrasound, computed tomography, and magnetic resonance. Differential diagnosis should exclude similar diseases such as CHARGE and Townes-Brocks syndromes and Fanconi anemia. New insights into genetic etiology have led to recommendations of chromosomal breakage investigation for optimal diagnosis and counseling.

Protocol for the development of a core outcome set for the optimisation of treatment and follow-up of patients with an anorectal malformation (ARM): The ARM and OUtcome Review (ARMOUR)-project

BACKGROUND

Primary treatment of an anorectal malformation (ARM) is surgical restoration of the anatomy. These children can experience many problems later in life; therefore, a long-term follow-up by an experienced team is needed. The aim of the ARM and OUtcome Review (ARMOUR-study) is to identify the lifetime outcomes that are important from a medical and patients' perspective and develop a core outcome set (COS) that can be implemented in a care pathway to support individual ARM management decisions.

METHODS

First, a systematic review will identify clinical and patient-reported outcomes described in studies conducted in patients with an ARM. Second, qualitative interviews with patients of different age categories and their caregivers will be held to ensure that the COS will include outcomes that are relevant from the patient's perspective. Finally, the outcomes will be taken forward to a Delphi consensus exercise. Using multiple web-based Delphi rounds, key stakeholders (medical experts, clinical researchers and patients) will prioritise outcomes. During a face-to-face consensus meeting, the final COS will be determined. These outcomes can be evaluated in a life-long care pathway for patients with ARM.

DISCUSSION

The development of a COS for ARMs aims to reduce heterogeneity in outcome reporting between (clinical) studies, enhancing the availability of comparable data, which will facilitate evidence-based patient care. Assessment of the outcomes in the COS during individual care pathways for ARM can support shared decisions regarding management. The ARMOUR-project has ethical approval and is registered with the Core Outcome Measures in Effectiveness Trials (COMET) initiative.

LEVEL OF EVIDENCE

Treatment study level II.

Prenatal diagnosis of VACTERL association after early-first trimester SARS-COV-2 infection

Organogenesis is a period of fetal development with a special vulnerability to biological and environmental agents. There are some viral infections whose transmission in the first trimester carries a significant risk for the development of congenital anomalies. Although the possibility of vertical transmission of SARS-CoV-2 during pregnancy has been demonstrated, there are no studies evaluating the impact of SARS-CoV-2 infection in the first trimester and its possible association with congenital anomalies. In this communication, we present the case of a pregnant woman with early SARS-CoV-2 infection, prenatally diagnosed with fetal VACTERL association by mid-trimester ultrasound. Further studies are needed to determine the causal association.

Patterns of multiple congenital anomalies in the National Birth Defect Prevention Study: Challenges and insights

BACKGROUND

About 20%-30% of children with birth defects have multiple major birth defects in more than one organ system, often referred to as multiple congenital anomalies (MCAs). Evaluating the patterns of MCAs can provide clues to the underlying causes, pathogenic mechanisms, and developmental pathways. We sought to explore selected patterns of MCAs within the National Birth Defects Prevention Study (NBDPS), a population-based, case-control study that excluded cases attributed to known chromosomal or single-gene abnormalities.

METHODS

We defined MCAs as having two or more NBDPS-eligible birth defects and calculated the adjusted observed-to-expected ratio for all observed MCA patterns using co-occurring defect analysis.

RESULTS

Of the 50,186 case infants eligible for NBDPS, 2,734 (3.7%) had at least two eligible birth defects. We observed 209 distinct 2-way combinations of birth defects, 297 distinct 3-way combinations, 179 distinct 4-way combinations, and 69 distinct 5-way combinations. Sacral agenesis had the largest proportion of cases with MCAs (70%), whereas gastroschisis had the lowest (3%). Among the cases with MCAs, 63% had a heart defect, 23% had an oral cleft, and 21% had anorectal atresia/stenosis. Of the patterns with adjusted observed-to-expected ratios in the top 20%, most were consistent with the known associations or syndromes, including VATER/VACTERL association and CHARGE syndrome.

CONCLUSIONS

Most but not all patterns that had the highest adjusted observed-to-expected ratios were instances of known syndromes or associations. These findings highlight the importance of considering birth defect combinations that suggest syndromic patterns in the absence of a formal syndromic diagnosis. New approaches for screening for sequences and associations, and VATER/VACTERL in particular, in surveillance systems with limited resources for manual review may be valuable for improving surveillance system quality. The observed MCA patterns within NBDPS may help focus future genetic studies by generating case groups of higher yield.

Exome sequencing efficacy and phenotypic expansions involving esophageal atresia/tracheoesophageal fistula plus

Esophageal atresia/tracheoesophageal fistula (EA/TEF) is a life-threatening birth defect that often occurs with other major birth defects (EA/TEF+). Despite advances in genetic testing, a molecular diagnosis can only be made in a minority of EA/TEF+ cases. Here, we analyzed clinical exome sequencing data and data from the DECIPHER database to determine the efficacy of exome sequencing in cases of EA/TEF+ and to identify phenotypic expansions involving EA/TEF. Among 67 individuals with EA/TEF+ referred for clinical exome sequencing, a definitive or probable diagnosis was made in 11 cases for an efficacy rate of 16% (11/67). This efficacy rate is significantly lower than that reported for other major birth defects, suggesting that polygenic, multifactorial, epigenetic, and/or environmental factors may play a particularly important role in EA/TEF pathogenesis. Our cohort included individuals with pathogenic or likely pathogenic variants that affect TCF4 and its downstream target NRXN1, and FANCA, FANCB, and FANCC, which are associated with Fanconi anemia. These cases, previously published case reports, and comparisons to other EA/TEF genes made using a machine learning algorithm, provide evidence in support of a potential pathogenic role for these genes in the development of EA/TEF.

Further description of two patients with biallelic variants in NADSYN1 in association with cardiac and vertebral anomalies

Congenital nicotinamide adenine dinucleotide (NAD) deficiency disorders are associated with pathogenic variants in the genes NADSYN1, HAAO, and KYNU. These disorders overlap with the anomalies present in vertebral, anal, cardiac, tracheoesophageal, radial and renal, and limb anomalies (VATER/VACTERL) association and often result in premature death. Children who survive typically have developmental delays or intellectual disability. Here, we describe two patients with compound heterozygous variants in NADSYN1 who presented with cardiac and vertebral defects overlapping with the VATER/VACTERL association, although the patients did not satisfy criteria for the diagnosis of VATER/VACTERL due to their lack of limb anomalies and significant renal anomalies. One patient survived into childhood with developmental delays and may represent an expansion of the survival data for NADSYN1-associated NAD deficiency disorders. Interestingly, one patient had hypoplastic left heart syndrome (HLHS) and one had an aortic coarctation and transverse hypoplasia of the aortic arch, suggesting that NADSYN1 sequencing should be performed in children presenting with congenital anomalies related to VATER/VACTERL association and with HLHS and aortic arch abnormalities.

Birth defect co-occurrence patterns in the Texas Birth Defects Registry

BACKGROUND

The population-level landscape of co-occurring birth defects among infants without a syndromic diagnosis is not well understood.

METHODS

We analyzed data from 40,771 infants with two or more major birth defects in the Texas Birth Defects Registry (TBDR; 1999-2014). We calculated adjusted observed-to-expected (O/E) ratios for all two, three, four, and five-way combinations of 138 major defects.

RESULTS

Among 530 patterns with the highest adjusted O/E ratios (top 5% of 10,595 patterns), 66% included only defects co-occurring within one organ system and 28% were suggestive of known patterns (e.g., midline developmental defects). Of the remaining patterns, the combination of defects with the highest O/E ratio (193.8) encompassed the diaphragm, spine, spleen, and heart defects. Fourteen patterns involved heart and spine defects with or without rib defects. Ten additional patterns primarily involved two hallmark components of VACTERL association (specifically, vertebral defects, anal atresia, cardiac defects, renal, or limb defects, but not tracheoesophageal fistula).

CONCLUSIONS

Our analyses provide a description of the birth defect co-occurrence patterns in a multi-ethnic, population-based sample, and revealed several patterns of interest. This work complements prior work that has suggested etiologic connections between select defects (e.g., diaphragmatic hernia and heart and spleen anomalies; heart and spine defects).

IMPACT

In this large-scale, population-based study of birth defect co-occurrence patterns, we found several birth defect combinations of potential interest that warrant further investigation: congenital diaphragmatic hernia, heart, spine, and spleen defects and scimitar syndrome with vertebral defects. The majority of patterns of co-occurring defects observed more frequently than expected involved multiple defects within the same system and combinations suggestive of known associations. Nearly all of the top patterns (beyond the same system and those suggestive of known associations) involved organ systems that are components of the VACTERL association, with heart, spine, and rib defect patterns being the most common.

Right Pulmonary Artery Originating from Ascending Aorta (Hemitruncus Arteriosus) with VACTERL Association in a Neonate: A Case Report

Vertebral, anal, cardiac, tracheo-esophageal fistula, renal and limb (VACTERL) association is defined as a condition including at least three of the above-mentioned anomalies in the same infant. Several cardiac defects that have been reported as a part of the VACTERL association are ventricular and atrial septal defects, hypoplastic left heart syndrome, transposition of the great arteries and tetralogy of Fallot. Anomalous origin of pulmonary artery (AOPA) from the ascending aorta is an unusual and critical cardiovascular anomaly, which frequently involves the right pulmonary artery (RPA). A male neonate was delivered by normal spontaneous vaginal delivery at 39 weeks and 3 days gestation, weighting 2660 gm. He was diagnosed with VACTERL association with five abnormalities: vertebral abnormalities, anal atresia, cardiovascular anomaly (right pulmonary artery originating from ascending aorta), tracheo-esophageal fistula and renal anomalies. AOPA origination from ascending aorta as part of the VACTERL association in a neonate is a rare congenital cardiovascular malformation. Here we present a rare case of RPA originating from the ascending aorta seen with VACTERL association in a neonate.

The Role of Sonic Hedgehog in Human Holoprosencephaly and Short-Rib Polydactyly Syndromes

The Hedgehog (HH) signalling pathway is one of the major pathways controlling cell differentiation and proliferation during human development. This pathway is complex, with HH function influenced by inhibitors, promotors, interactions with other signalling pathways, and non-genetic and cellular factors. Many aspects of this pathway are not yet clarified. The main features of Sonic Hedgehog (SHH) signalling are discussed in relation to its function in human development. The possible role of SHH will be considered using examples of holoprosencephaly and short-rib polydactyly (SRP) syndromes. In these syndromes, there is wide variability in phenotype even with the same genetic mutation, so that other factors must influence the outcome. SHH mutations were the first identified genetic causes of holoprosencephaly, but many other genes and environmental factors can cause malformations in the holoprosencephaly spectrum. Many patients with SRP have genetic defects affecting primary cilia, structures found on most mammalian cells which are thought to be necessary for canonical HH signal transduction. Although SHH signalling is affected in both these genetic conditions, there is little overlap in phenotype. Possible explanations will be canvassed, using data from published human and animal studies. Implications for the understanding of SHH signalling in humans will be discussed.

Heterozygous loss of WBP11 function causes multiple congenital defects in humans and mice

The genetic causes of multiple congenital anomalies are incompletely understood. Here, we report novel heterozygous predicted loss-of-function (LoF) and predicted damaging missense variants in the WW domain binding protein 11 (WBP11) gene in seven unrelated families with a variety of overlapping congenital malformations, including cardiac, vertebral, tracheo-esophageal, renal and limb defects. WBP11 encodes a component of the spliceosome with the ability to activate pre-messenger RNA splicing. We generated a Wbp11 null allele in mouse using CRISPR-Cas9 targeting. Wbp11 homozygous null embryos die prior to E8.5, indicating that Wbp11 is essential for development. Fewer Wbp11 heterozygous null mice are found than expected due to embryonic and postnatal death. Importantly, Wbp11 heterozygous null mice are small and exhibit defects in axial skeleton, kidneys and esophagus, similar to the affected individuals, supporting the role of WBP11 haploinsufficiency in the development of congenital malformations in humans. LoF WBP11 variants should be considered as a possible cause of VACTERL association as well as isolated Klippel-Feil syndrome, renal agenesis or esophageal atresia.

Fifty years of recognizable patterns of human malformation: Insights and opportunities

Now in its 7th edition, Smith's Recognizable Patterns of Human Malformation was first published in 1970. This 1st edition comprised 135 "dysmorphic syndromes of multiple primary defects" and 12 "single syndromic malformations resulting in secondary defects." Of the former, other than a few chromosomal and environmental disorders, most were heritable conditions of then unknown etiology. In 2021, the majority of these conditions are now "solved," a notable exception is Hallermann-Streiff syndrome. The "solved" conditions were typically clinically delineated decades prior to understanding the underlying etiology, which rarely required recent technologies such as exome sequencing (ES) to elucidate. The 7th edition includes nearly 300 syndromes, sequences, and associations. An increasing number of conditions first appearing in the latest editions are sporadic, with many solved using either array CGH or ES. We have reviewed all syndromes that have appeared in "Smith's" with a focus on inheritance, heterogeneity, and year and method of etiologic discovery. Several themes emerge. Genetic heterogeneity and pleiotropy of genes are frequent. Several of the currently "unresolved" syndromes are clinically diverse such as Dubowitz syndrome. Multiple recurrent constellations of embryonic malformations, with VACTERL association as a paradigm, are increasingly likely to have a shared pathogenesis requiring further study.

Accompanied anomalies in anal atresia or tracheo-esophageal fistula: Comparison with or without VACTERL association

PURPOSE

We evaluated the various accompanied malformations in patients with anal atresia or tracheoesophageal fistula (TEF). Furthermore, we determined the prevalence of VACTERL association and compared the clinical findings with those of patients without VACTERL association.

METHODS

We enrolled the patients with anal atresia or TEF with/without esophageal atresia. We collected the patient data pertaining to accompanied vertebral, cardiovascular, renal or limb anomalies, single umbilical artery, maternal diabetes mellitus or drug history, and gene research.

RESULTS

A total 155 patients (65 boys and 90 girls) were enrolled with 147 cases of anal atresia, 3 cases of TEF, and 5 cases of anal atresia with TEF. The prevalence of accompanied anomalies was 67.1% in cardiovascular, 27.1% in renal, 9.7% in vertebral, 2.6% in limb anomalies, and 3.9% in single umbilical artery. Thirty-six (23.2%) patients were diagnosed with VACTERL association. The patients with VACTERL association had a significantly higher number of male patients (58.3 vs. 37.0%, p = .033) and single umbilical artery (11.1 vs. 1.7%, p = .026), and had a significantly lower birth weight (2.8 vs. 3.1 kg, p = .033) than the patients without VACTERL association. Genetic studies were performed in 111 patients, and 8 (7.2%) had chromosomal abnormalities-3 in VACTERL and 5 in no VACTERL group.

CONCLUSION

We recommend a careful evaluation for VACTERL association in patients with anal atresia or TEF. It is particularly important to screen for a single umbilical artery for features of VACTERL association as well as for other congenital anomalies.

The embryology of persistent cloaca and urogenital sinus malformations

Cloacal malformations are characterized by the confluence of the lower urinary tract, the female reproductive tract, and the rectum to create a common channel with a single opening on the perineum. The presence of a cloaca is a normal phase of early human embryological development. Between the 4^th and 7^th weeks of gestation, the cloaca undergoes subdivision to form the hindgut and urogenital sinus. Failure of this process results in the congenital anomaly termed persistent cloaca (PC). The term urorectal septum malformation sequence (URSMS) is also used to describe this anomaly. The classic description of this process which is still cited in many standard textbooks dates from the 19^th century. However, this has been increasingly called into question by the findings of studies using modern scientific methodology. Urogenital sinus anomalies are defined by the confluence of the urethra and vagina to form a common channel of varying length with a single perineal opening. In this condition, the anorectal canal opens separately on the perineum. The presence of a urogenital sinus represents a transient phase of the normal development of the lower genital tract in the female fetus. However, the form of urogenital sinus most commonly encountered in the developed world is a feature of disordered sexual differentiation and does not arise simply from the persistence of the anatomical structure which is a feature of normal fetal development.

The Classification of VACTERL Association into 3 Groups According to the Limb Defect

The VACTERL association (VA) is defined as the nonrandom co-occurrence of 6 anomalies: vertebral anomalies (V), Anal atresia (A), Cardiac defects (C), Tracheo-esophageal fistula (TE), Renal defects (R), and Limb anomalies (L). The current communication presents an argument that patients with VA should be classified into three district groups based on their limb defects: VACTERL1: patients with normal limbs; VACTERL2: patients with limb anomalies other than radial ray defects of the upper limbs; and VACTERL3: patients with radial ray defects of the upper limbs. The author will demonstrate that the rationale behind the L1-3 classification in patients in VA is based on the embryogenesis of the 6 affected anatomical areas in VA. The pathogenesis of VACTERL1 is secondary to perturbations of Sonic Hedgehog (SHH) interactions. SHH signaling is known to have a major role in the normal development of the vertebrae, ano-rectal area, heart, tracheo-esophageal area, and kidney. However, SHH is not involved in the development of the radial ray; hence, patients present with no limb defects. The pathogenesis of VACTERL2 is variable depending on the type of gene mutation. The pathogenesis of VACTERL3 is related to errors in a group of proteins (namely, the proteins of the TBX5-SALL4-SALL1 loop and the FGF8-FGF10 loop/ pathway). These proteins are essential for the normal development of the radial ray and they interact in the development of the other anatomical areas of VA including the heart and kidney. Hence, VACTERL3 patients present with radial ray deficiency.

Common pathogenesis for sirenomelia, OEIS complex, limb-body wall defect, and other malformations of caudal structures

Decades of clinical, pathological, and epidemiological study and the recent application of advanced microarray and gene sequencing technologies have led to an understanding of the causes and pathogenesis of most recognized patterns of malformation. Still, there remain a number of patterns of malformation whose pathogenesis has not been established. Six such patterns of malformation are sirenomelia, VACTERL association, OEIS complex, limb-body wall defect (LBWD), urorectal septum malformation (URSM) sequence, and MURCS association, all of which predominantly affect caudal structures. On the basis of the overlap of the component malformations, the co-occurrence in individual fetuses, and the findings on fetal examination, a common pathogenesis is proposed for these patterns of malformation. The presence of a single artery in the umbilical cord provides a visible clue to the pathogenesis of all cases of sirenomelia and 30%-50% of cases of VACTERL association, OEIS complex, URSM sequence, and LBWD. The single artery is formed by a coalescence of arteries that supply the yolk sac, arises from the descending aorta high in the abdominal cavity, and redirects blood flow from the developing caudal structures of the embryo to the placenta. This phenomenon during embryogenesis is termed vitelline vascular steal.

Phenotypic Characteristics and Copy Number Variants in a Cohort of Colombian Patients with VACTERL Association

VACTERL association (OMIM 192350) is a heterogeneous clinical condition characterized by congenital structural defects that include at least 3 of the following features: vertebral abnormalities, anal atresia, heart defects, tracheoesophageal fistula, renal malformations, and limb defects. The nonrandom occurrence of these malformations and some familial cases suggest a possible association with genetic factors such as chromosomal alterations, gene mutations, and inherited syndromes such as Fanconi anemia (FA). In this study, the clinical phenotype and its relationship with the presence of chromosomal abnormalities and FA were evaluated in 18 patients with VACTERL association. For this, a G-banded karyotype, array-comparative genomic hybridization, and chromosomal fragility test for FA were performed. All patients (10 female and 8 male) showed a broad clinical spectrum: 13 (72.2%) had vertebral abnormalities, 8 (44.4%) had anal atresia, 14 (77.8%) had heart defects, 8 (44.4%) had esophageal atresia, 10 (55.6%) had renal abnormalities, and 10 (55.6%) had limb defects. Chromosomal abnormalities and FA were ruled out. In 2 cases, the finding of microalterations, namely del(15)(q11.2) and dup(17)(q12), explained the phenotype; in 8 cases, copy number variations were classified as variants of unknown significance and as not yet described in VACTERL. These variants comprise genes related to important cellular functions and embryonic development.

Discovering Genotype Variants in an Infant with VACTERL through Clinical Exome Sequencing: A Support for Personalized Risk Assessment and Disease Prevention

Congenital anomalies may have an increased risk of noncommunicable diseases (NCDs) We performed a clinical exome analysis in an infant affected by "Vertebral, Anorectal, Cardiac, Tracheoesophageal, Genitourinary, and Limb" (VACTERL) malformation association to identify potential biomarkers that may be helpful for preventing malignancy risk or other chronic processes. Among the variants, six variants that may be linked with VACTERL were identified in the exome analysis. The variants c.501G>C on OLR1 and c.-8C>G on PSMA6 were previously associated with myocardial infarction. The variants c.1936A>G on AKAP10 and c.575A>G on PON1 are linked to defects in cardiac conduction and artery disease, respectively. Alterations in metabolism were also suggested by the variants c.860G>A on EPHX2 and c.214C>A on GHRL. In addition, three variants associated with colon cancer were discovered. Specifically, the reported variants were c.723G>A on CCND1 and c.91T>A on AURKA proto-oncogenes as well as c.827A>C in the tumor suppressor PTPRJ. A further inspection identified 15 rare variants carried by cancer genes. Specifically, these mutations are located on five tumor suppressors (SDHA, RB1CC1, PTCH1, DMBT1, BCR) and eight proto-oncogenes (MERTK, CSF1R, MYB, ROS1, PCM1, FGFR2, MYH11, BRCC3) and have an allele frequency lower than 0.01 in the Genome Aggregation Database (GnomAD). We observed that the cardiac and metabolic phenotypic traits are linked with the genotype of the patient. In addition, the risk of developing neoplasia cannot be excluded a priori. Long-term surgical issues of patients with VATER syndrome could benefit from the clinical exome sequencing of a personalized risk assessment for the appearance of further disease in pubertal timing and adult age.

Clinical and epidemiological features of heart-hand syndrome, an updated analysis in China

BACKGROUND

The purpose of this study was to prospectively recruit patients treated with limb malformation and to explore the prevalence and the clinical and epidemiological features of Heart-Hand Syndrome (HHS) in China.

METHODS

The consecutive patients treated for congenital upper limb malformation in Beijing Ji Shui Tan Hospital from October 1st, 2016 to October 1st, 2019 were prospectively recruited. We reviewed the patients' medical records and identified patients with abnormal electrocardiogram (ECG) and/or abnormal ultrasonic cardiogram as well as their basic demographic and clinical characteristics.

RESULTS

A total 1653 (1053 male and 600 female) patients with congenital upper extremity malformations were prospectively recruited. Among them, 200 (12.1%) had abnormal ultrasonic cardiogram (181patients, 10.9%) and/or abnormal ECG (19 patients, 1.1%). The commonest type of abnormal heart structure was atrial septal defect (69/181 38.1%), and the commonest abnormal ECG was wave patterns (7/19, 36.8%). HHS patients had a higher comorbidity rate (11%) than non-HHS patients (6.9%). Patients with HHS were classified into four groups by the types of congenital upper extremity malformations, among which the most common group was thumb type (121/200, 60.5%).

CONCLUSIONS

HHS occurred frequently among patients with congenital upper extremity malformation in China, particularly for those with multiple congenital malformations. The commonest type of hand malformations of HHS patients was thumb malformation.

Association of Radial Longitudinal Deficiency and Thumb Hypoplasia: An Update Using the CoULD Registry

BACKGROUND

Deficiency of the radial aspect of the forearm and hand is the most common congenital longitudinal deficiency of the upper limb. Radial longitudinal deficiency is associated with several named syndromes. The purpose of the present study was to explore patterns of radial longitudinal deficiency and thumb hypoplasia in syndromes and to examine the severity of these differences across various syndromes.

METHODS

Data were collected from the Congenital Upper Limb Differences (CoULD) registry. Congenital differences are classified in the registry with use of the Oberg-Manske-Tonkin (OMT) classification system. Diagnosis of a syndrome by a physician as noted in the CoULD registry was recorded. Thumb deficiency and radial deficiency were classified according to the modified versions of the Blauth criteria and the Bayne and Klug criteria, respectively.

RESULTS

We identified 259 patients with 383 affected limbs with radial deficiency. Eighty-three of these patients had a diagnosed syndrome. The severity of radial deficiency was correlated with the severity of thumb deficiency. The Kendall tau coefficient indicated significant correlation between radial severity and thumb severity (tau = 0.49 [95% confidence interval = 0.40 to 0.57]; p < 0.05). Subjects with a syndrome were twice as likely to have bilateral deficiency and 2.5 times more likely to have both radial and thumb deficiency compared with subjects without a syndrome. Subjects with VACTERL syndrome (vertebral defects, anal atresia, cardiac anomalies, tracheoesophageal fistula, renal anomalies, and limb defects) had patterns of thumb and radial deficiency similar to the general cohort, whereas subjects with Holt-Oram syndrome, TAR (thrombocytopenia absent radius) syndrome, and Fanconi anemia demonstrated varied presentations of thumb and radial deficiency.

CONCLUSIONS

The present study investigated the characteristics of patients with radial longitudinal deficiency and thumb hypoplasia. Our results support the findings of previous research correlating the severity of radial deficiency with the severity of thumb deficiency. Furthermore, we identified characteristic features of patients with radial longitudinal deficiency and associated syndromes.

Congenital microgastria-limb reduction association: A case report and review of the literature

We report a patient with phenotypic semblance to the congenital microgastria-limb reduction association (MLRD). Our patient presented with microgastria, bilateral upper limb anomalies, asplenia, solitary kidney, and mild micrognathia. In addition to the anomalies seen in our patient, MLRD has been associated with respiratory, cardiovascular, and central nervous system anomalies. MLRD is thought to arise from a developmental field defect during embryonic weeks five and six; however, no genetic cause has been elucidated. Along with our patient presentation, we review the literature to further our understanding of the MLRD phenotype spectrum.

Recurrent constellations of embryonic malformations re-conceptualized as an overlapping group of disorders with shared pathogenesis

Several recurrent malformation associations affecting the development of the embryo have been described in which a genetic etiology has not been found, including LBWC, MURCS, OAVS, OEIS, POC, VACTERL, referred to here as "recurrent constellations of embryonic malformations" (RCEM). All are characterized by an excess of reported monozygotic discordant twins and lack of familial recurrence. We performed a comprehensive review of published twin data across all six phenotypes to allow a more robust assessment of the association with twinning and potential embryologic timing of a disruptive event. We recorded the type of twinning, any overlapping features of another RCEM, maternal characteristics, and the use of ART. Statistically significant associations included an excess of monozygotic twins and 80% discordance rate for the phenotype across all twins. There was an 18.5% rate of ART and no consistently reported maternal adverse events during pregnancy. We found 24 instances of co-occurrence of two RCEM, suggesting a shared pathogenesis across all RCEM phenotypes. We hypothesize the following timing for RCEM phenotypes from the earliest perturbation in development to the latest: LBWC, POC, OEIS, VACTERL, OAVS, then MURCS. The RCEM group of conditions should be considered a spectrum that could be studied as a group.

Management of Esophageal Lung in a Patient With VACTERL Anomalies

Esophageal lung is a rare type of bronchopulmonary foregut malformation where an anomalous main bronchus arises from the esophagus rather than the trachea. This differentiates from an esophageal bronchus where a lobar bronchus arises from the esophagus. Fewer than 30 of these anomalies have been reported in the literature. A female infant was born at 35 weeks gestational age and found to have multiple congenital abnormalities including cleft palate, long-gap esophageal atresia, tracheoesophageal fistula (TEF), imperforate anus, and renal anomalies. She initially underwent thoracoscopic ligation of TEF with colostomy and mucus fistula creation. Bronchoscopy found no right mainstem bronchus, and subsequent computed tomography scan was consistent with possible esophageal bronchus. Esophagoscopy through the gastrostomy discovered a fistulous connection between the distal esophagus and anomalous main right bronchus.Right thoracotomy with pneumonectomy of the hypoplastic lung was performed. She subsequently underwent vaginostomy for hydrometrocolpos. Her proximal esophagus was diverted with a cervical esophagostomy for control of secretions. She also required tracheotomy and is currently at home on minimal ventilator settings awaiting staged reconstruction.Esophageal lung is a rare congenital abnormality with few reported cases. Surgical treatment with pneumonectomy is often required, and pediatric surgeons should be familiar with these congenital bronchopulmonary malformations.

Spinal dysraphism as a new entity in V.A.C.TE.R.L syndrome, resulting in a novel acronym V.A.C.TE.R.L.S

Anorectal malformation (ARM) is the most common symptom in VACTERL syndrome (vertebral, anal, cardiac, tracheo-esophageal fistula, renal, and limb anomalies). The association of ARM and spinal dysraphisms (DYS) is well documented. We aim to better evaluate children with VACTERL association and ARM, considering the presence or not of DYS. Between 2000 and 2015, 279 children with VACTERL associations were identified in Necker Children's Hospital, Paris. We identified 61 VACTERL children (22%) with ARM. A total of 52 VACTERL children with ARM were included. DYS were identified in 36/52 of cases (69.2%). A total of 33 (63.5%) VACTERL children presented with sphincterial dysfunction. We constated that 28/33 (84.8%) of them had DYS + (p < 0.0001). More children in ARM (DYS +) subgroup are presenting with initial urinary sphincter dysfunction (58 vs 19%, p < 0.009) than ARM (DYS -). We identified 29 lipoma filum in our series, which were not statistically associated with urinary disorders (p = 0.143).Conclusion: We propose to refine the definition of VACTERL association, by adding S as Spinal defect to include it as an integral part of this syndrome, resulting in a novel acronym V.A.C.TE.R.L.S.What is Known:• The VACTERL association: congenital anomalies of the bony vertebral column (V), anorectal malformation (A), congenital cardiopathy (C), tracheo-esophageal defects (TE), renal and urinary tract anomalies (R), and limb malformations (L).• VACTERL children needs a complete appraisal, as early as possible, to adopt the most appropriate therapeutic management.What is New:• Include spine dysraphism (DYS) as a part of this syndrome, resulting in a novel acronym V.A.C.TE.R.L.S.• The significant correlation between VACTERL/DYS and urinary dysfunction requires to investigate the spine cord prenatally.

Exome Sequencing and Identification of Phenocopies in Patients With Clinically Presumed Hereditary Nephropathies

RATIONALE & OBJECTIVE

Hereditary nephropathies are clinically and genetically heterogeneous disorders. For some patients, the clinical phenotype corresponds to a specific hereditary disease but genetic testing reveals that the expected genotype is not present (phenocopy). The aim of this study was to evaluate the spectrum and frequency of phenocopies identified by using exome sequencing in a cohort of patients who were clinically suspected to have hereditary kidney disorders.

STUDY DESIGN

Cross-sectional cohort study.

SETTING & PARTICIPANTS

174 unrelated patients were recruited for exome sequencing and categorized into 7 disease groups according to their clinical presentation. They included autosomal dominant tubulointerstitial kidney disease, Alport syndrome, congenital anomalies of the kidney and urinary tract, ciliopathy, focal segmental glomerulosclerosis/steroid-resistant nephrotic syndrome, VACTERL association, and "other."

RESULTS

A genetic diagnosis (either likely pathogenic or pathogenic variant according to the guidelines of the American College of Medical Genetics) was established using exome sequencing in 52 of 174 (30%) cases. A phenocopy was identified for 10 of the 52 exome sequencing-solved cases (19%), representing 6% of the total cohort. The most frequent phenocopies (n=5) were associated with genetic Alport syndrome presenting clinically as focal segmental glomerulosclerosis/steroid-resistant nephrotic syndrome. Strictly targeted gene panels (<25 kilobases) did not identify any of the phenocopy cases.

LIMITATIONS

The spectrum of described phenocopies is small. Selection bias may have altered the diagnostic yield within disease groups in our study population. The study cohort was predominantly of non-Finnish European descent, limiting generalizability. Certain hereditary kidney diseases cannot be diagnosed by using exome sequencing (eg, MUC1-autosomal dominant tubulointerstitial kidney disease).

CONCLUSIONS

Phenocopies led to the recategorization of disease and altered clinical management. This study highlights that exome sequencing can detect otherwise occult genetic heterogeneity of kidney diseases.

Maternal risk factors for the VACTERL association: A EUROCAT case-control study

BACKGROUND

The VACTERL association (VACTERL) is the nonrandom occurrence of at least three of these congenital anomalies: vertebral, anal, cardiac, tracheoesophageal, renal, and limb anomalies. Despite suggestions for involvement of several genes and nongenetic risk factors from small studies, the etiology of VACTERL remains largely unknown.

OBJECTIVE

To identify maternal risk factors for VACTERL in offspring in a large European study.

METHODS

A case-control study was performed using data from 28 EUROCAT registries over the period 1997-2015 with case and control ascertainment through hospital records, birth and death certificates, questionnaires, and/or postmortem examinations. Cases were diagnosed with VACTERL, while controls had a genetic syndrome and/or chromosomal abnormality. Data collected included type of birth defect and maternal characteristics, such as age, use of assisted reproductive techniques (ART), and chronic illnesses. Multivariable logistic regression analyses were performed to estimate confounder adjusted odds ratios (aOR) with 95% confidence intervals (95% CI).

RESULTS

The study population consisted of 329 VACTERL cases and 49,724 controls with recognized syndromes or chromosomal abnormality. For couples who conceived through ART, we found an increased risk of VACTERL (aOR 2.3 [95% CI 1.3, 3.9]) in offspring. Pregestational diabetes (aOR 3.1 [95% CI 1.1, 8.6]) and chronic lower obstructive pulmonary diseases (aOR 3.9 [95% CI 2.2, 6.7]) also increased the risk of having a child with VACTERL. Twin pregnancies were not associated with VACTERL (aOR 0.6 [95% CI 0.3, 1.4]).

CONCLUSION

We identified several maternal risk factors for VACTERL in offspring befitting a multifactorial etiology.

Unsolved recognizable patterns of human malformation: Challenges and opportunities

Due to the efforts of the clinical and scientific communities and boosted by recent advances in genetic technologies, we now understand the molecular mechanisms underlying most of the frequent and recognizable human malformation syndromes. However, some well-established human malformation syndromes remain without a molecular diagnosis despite intensive investigation. This issue of Seminars mines the phenotypic entries in OMIM and estimates that of the documented 2,034 unsolved entries likely to represent a rare genetic disease, only 160 are well-established and possibly amenable to investigation. This issue also reviews well-characterized and extensively investigated human malformation syndromes and associations that remain unsolved, including the following: Dubowitz syndrome (MIM 223370%), Hallermann-Streiff syndrome (MIM 234100%), PHACE syndrome (MIM 606519), Oculocerebrocutaneous syndrome (MIM 164180), Aicardi syndrome (MIM 304050%), Gomez-Lopez-Hernandez syndrome and Rhombencephalosynapsis (MIM 601853%), VACTERL (MIM 192350%), and Nablus syndrome (MIM #608156). Possible explanations for their intractability to molecular diagnosis are explored, including genetic and phenotypic heterogeneity, mosaicism, epigenetics, gene-environment interactions, and other non-Mendelian contributions. Finally, this issue of Seminars presents a path forward for these unsolved rare conditions and suggests a renewed focus on solving amendable OMIM disorders. It is clear that the way forward will require new technologies, global cooperation, and data sharing; these will also be necessary to help reach the vision of the International Rare Diseases Research Consortium (IRDiRC), that is to enable all people living with a rare disease to receive an accurate diagnosis, care and available therapy within 1 year of coming to medical attention.

VACTERL Association in a Female Pig (Sus scrofa domesticus)

VACTERL/VATER association is a condition defined by the presence of at least three of the following congenital malformations: vertebral defects (V), anal atresia (A), cardiac defects (C), tracheo-oesophageal fistula (TE), renal anomalies (R) and limb abnormalities (L). We describe a stillborn female piglet with cardiac anomalies, renal defects, vertebral anomalies, anal atresia and a single umbilical artery (SUA), which are the main features of VACTERL association. In addition, the piglet had a unilateral abdominal wall defect. This was the only affected animal in a litter of 16 piglets. The molecular inductive mechanisms of this disorder are discussed, as well as the comparative and embryological implications.

Yq Microdeletion in a Patient with VACTERL Association and Shawl Scrotum with Bifid Scrotum: A Real Pathogenetic Association or a Coincidence?

VACTERL association is defined by the occurrence of congenital malformations: vertebral defects, anal atresia, cardiac defects, tracheoesophageal fistula with esophageal atresia, radial and renal dysplasia, and limb defects. No genetic alterations have been discovered except for some sporadic chromosomal rearrangements and gene mutations. We report a boy with VACTERL association and shawl scrotum with bifid scrotum who presented with a de novo Yq11.223q11.23 microdeletion identified by array CGH. The deletion spans 3.1 Mb and encompasses several genes in the AZFc region, frequently deleted in infertile men with severe oligozoospermia or azoospermia. Herein, we discuss the possible explanation for this unusual genotype-phenotype correlation. We suggest that the deletion of the BPY2 (previously VCY2) gene, located in the AZFc region and involved in spermatogenesis, contributed to the genesis of the phenotype. In fact, BPY2 interacts with a ubiquitin-protein ligase, involved in the SHH pathway which is known to be implicated in the genesis of VACTERL association.