Re-sequencing of candidate genes FOXF1, HSPA6, HAAO, and KYNU in 522 individuals with VATER/VACTERL, VACTER/VACTERL-like association, and isolated anorectal malformation

Practical Approach to Congenital Anomalies of the Kidneys: Focus on Anomalies With Insufficient or Abnormal Nephron Development: Renal Dysplasia, Renal Hypoplasia, and Renal Tubular Dysgenesis

Congenital anomalies of the kidney and urinary tract (CAKUT) accounts for up to 30% of antenatal congenital anomalies and is the main cause of kidney failure in children worldwide. This review focuses on practical approaches to CAKUT, particularly those with insufficient or abnormal nephron development, such as renal dysplasia, renal hypoplasia, and renal tubular dysgenesis. The review provides insights into the histological features, pathogenesis, mechanisms, etiologies, antenatal and postnatal presentation, management, and prognosis of these anomalies. Differential diagnoses are discussed as several syndromes may include CAKUT as a phenotypic component and renal dysplasia may occur in some ciliopathies, tumor predisposition syndromes, and inborn errors of metabolism. Diagnosis and genetic counseling for CAKUT are challenging, due to the extensive variability in presentation, genetic and phenotypic heterogeneity, and difficulties to assess postnatal lung and renal function on prenatal imaging. The review highlights the importance of perinatal autopsy and pathological findings in surgical specimens to establish the diagnosis and prognosis of CAKUT. The indications and the type of genetic testing are discussed. The aim is to provide essential insights into the practical approaches, diagnostic processes, and genetic considerations offering valuable guidance for pediatric and perinatal pathologists.

A novel genotype-phenotype between persistent-cloaca-related VACTERL and mutations of 8p23 and 12q23.1

The mechanism underlying anorectal malformations (ARMs)-related VACTERL (vertebral defects, anal atresia, cardiac defects, tracheo-esophageal fistula, and renal and limb abnormalities) remains unclear. Copy number variation (CNV) contributed to VACTERL pathogenicity. Here, we report a novel CNV in 8p23 and 12q23.1 identified in a case of ARMs-related VACTERL association. This 12-year-old girl presented a cloaca (urethra, vagina, and rectum opening together and sharing a single tube length), an isolated kidney, and a perpetuation of the left superior vena cava at birth. Her intelligence, growth, and development were slightly lower than those of normal children of the same age. Array comparative genomic hybridization revealed a 9.6-Mb deletion in 8p23.1-23.3 and a 0.52-Mb duplication in 12q23.1 in her genome. Furthermore, we reviewed the cases involving CNVs in patients with VACTERL, 8p23 deletion, and 12q23.1 duplication, and our case was the first displaying ARMs-related VACTERL association with CNV in 8p23 and 12q23.1. These findings enriched our understanding between VACTERL association and the mutations of 8p23 deletion and 12q23.1 duplication. IMPACT: This is a novel case of a Chinese girl with anorectal malformations (ARMs)-related VACTERL with an 8p23.1-23.3 deletion and 12q23.1 duplication. Cloaca malformation is presented with novel copy number variation in 8p23.1-23.3 deletion and 12q23.1 duplication.

Tracheal agenesis versus tracheal atresia: anatomical conditions, pathomechanisms and causes with a possible link to a novel MAPK11 variant in one case

BACKGROUND

In this study we aimed to describe the morphological and pathogenetic differences between tracheal agenesis and tracheal atresia, which are not clearly distinguished from each other in the literature, and to contribute thereby to the understanding and management of these conditions. Both tracheal agenesis and tracheal atresia represent rare disorders of still unknown aetiology that cannot be detected by prenatal ultrasound. If the affected foetuses survive until birth these conditions result in respiratory failure and in futile attempts to rescue the infant's life.

RESULTS

Autopsies and genetic analyses, including singleton or trio exome sequencing, were performed on five neonates/foetuses with tracheal agenesis and three foetuses with tracheal atresia. Tracheal agenesis was characterized by absence of the sublaryngeal trachea and presence of a bronchooesophageal fistula and by pulmonary isomerism and occurred as an isolated malformation complex or as part of a VACTERL association. Special findings were an additional so-called 'pig bronchus' and a first case of tracheal agenesis with sirenomelia. Tracheal atresia presenting with partial obliteration of its lumen and persistence of a fibromuscular streak resulted in CHAOS. This condition was associated with normal lung lobulation and single, non-VACTERL type malformations. Trio ES revealed a novel variant of MAPK11 in one tracheal agenesis case. Its involvement in tracheooesophageal malformation is herein discussed, but remains hypothetical.

CONCLUSION

Tracheal agenesis and tracheal atresia represent different disease entities in terms of morphology, pathogenesis and accompanying anomalies due to a primary developmental and secondary disruptive possibly vascular disturbance, respectively.

Pulmonary Hypertension in Developmental Lung Diseases

Diverse genetic developmental lung diseases can present in the neonatal period with hypoxemic respiratory failure, often associated with with pulmonary hypertension. Intractable hypoxemia and lack of sustained response to medical management should increase the suspicion of a developmental lung disorder. Genetic diagnosis and lung biopsy are helpful in establishing the diagnosis. Early diagnosis can result in optimizing management and redirecting care if needed. This article reviews normal lung development, various developmental lung disorders that can result from genetic abnormalities at each stage of lung development, their clinical presentation, management, prognosis, and differential diagnoses.

Updated EUROCAT guidelines for classification of cases with congenital anomalies

BACKGROUND

Precise and correct classification of congenital anomalies is important in epidemiological studies, not only to classify according to etiology but also to group similar congenital anomalies together, to create homogeneous subgroups for surveillance and research. This paper presents the updated EUROCAT (European surveillance of congenital anomalies) subgroups of congenital anomalies and the updated multiple congenital anomaly (MCA) algorithm and provides the underlying arguments for the revisions.

METHODS

The EUROCAT methodology is described. In addition, we show how we validated the revised EUROCAT subgroups and MCA algorithm, which are both based on the International Classification of Diseases (ICD10/ICD9) codes.

RESULTS

The updated EUROCAT subgroups and the updated MCA algorithm are described in detail and the updated version is compared to the previous versions.

CONCLUSION

The EUROCAT subgroups and MCA algorithm provide a standardized and clear methodology for congenital anomaly research and epidemiological surveillance of congenital anomalies in order to facilitate the identification of teratogenic exposures and to assess the impact of primary prevention and prenatal screening policies. The EUROCAT subgroups and MCA algorithm are made freely available for other researchers via the EUROCAT Database Management Software.

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.

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.