Sacral agenesis: a pilot whole exome sequencing and copy number study

Sacral Agenesis: Late Presentation and the Psychological Impact of Delayed Diagnosis

Sacral agenesis (SA) is a rare condition characterized by the absence of one or more lower sacral vertebral bodies. In India, children with this condition often present late with symptoms primarily related to urinary and bowel dysfunction. Maternal diabetes is the only confirmed risk factor, significantly elevating the incidence rate. We discuss a case of a nine-year-old female who presented to the pediatric outpatient department (OPD) with chronic constipation and urinary retention, having experienced symptoms since infancy. Initial investigations at peripheral hospitals had yielded no clear diagnosis, leading to undue psychological distress to the child and family. The child had been born to a mother with diabetes mellitus during pregnancy. Physical examination revealed mild dehydration, anemia, and sacral dimpling. Further evaluation showed renal injury and SA confirmed by MRI, along with other associated findings. This case report highlights the importance of early diagnosis and intervention in pediatric SA, especially given the risk of renal disease progression. The treatment in this case included clean intermittent self-catheterization (CIC), dietary management, and counseling on renal health. Crucially, uncovering the root cause provided immense psychological relief to the child and her family. Pediatric SA remains a diagnostic challenge, often leading to psychological distress in affected individuals who present late. Early recognition and comprehensive management are crucial, especially in cases associated with maternal diabetes, to mitigate the risk of renal complications and improve the overall quality of life for affected children.

Caudal Regression Syndrome-A Narrative Review: An Orthopedic Point of View

Abnormalities in cellular differentiation during embryo-fetal period may lead to various malformations of the spine. Caudal regression syndrome (CRS) is a group of defects with premature growth/development termination of the vertebral column. CRS can be divided into three types: sirenomelia, complete absence of the sacrum and partial absence of the sacrum. Genitourinary and gastrointestinal anomalies are common, with neurogenic bladder and bowel incontinence. Treatment of patients with CRS is complex and multidisciplinary and should be comprehensive. The most common orthopedic problems are: spinal deformity (kyphosis and scoliosis), spinopelvic instability and lower limbs deformities.

Diabetic Embryopathies

Diabetic embryopathy is defined as congenital anomalies that are linked to maternal diabetes. The association between diabetes and fetal, neonatal, and long-term complications is well-established. These complications include organ or structural maldevelopment, fetal growth abnormalities, and learning/psychiatric comorbidities. Recent studies have elucidated the pathophysiology behind these conditions and outlined new management approaches. Caudal regression syndrome, also known as sacral agenesis, is a well-known but less described complication of maternal diabetes. The purpose of this review is to summarize existing research on common neonatal morbidities in infants of mothers with diabetes with a focus on caudal regression syndrome and its long-term associations.

Epigenome-wide gene–age interaction study reveals reversed effects of MORN1 DNA methylation on survival between young and elderly oral squamous cell carcinoma patients

DNA methylation serves as a reversible and prognostic biomarker for oral squamous cell carcinoma (OSCC) patients. It is unclear whether the effect of DNA methylation on OSCC overall survival varies with age. As a result, we performed a two-phase gene–age interaction study of OSCC prognosis on an epigenome-wide scale using the Cox proportional hazards model. We identified one CpG probe, cg11676291_MORN1, whose effect was significantly modified by age (HR_discovery = 1.018, p = 4.07 × 10⁻⁰⁷, FDR-q = 3.67 × 10⁻⁰²; HR_validation = 1.058, p = 8.09 × 10⁻⁰³; HR_combined = 1.019, p = 7.36 × 10⁻¹⁰). Moreover, there was an antagonistic interaction between hypomethylation of cg11676291_MORN1 and age (HR_interaction = 0.284; 95% CI, 0.135–0.597; p = 9.04 × 10⁻⁰⁴). The prognosis of OSCC patients was well discriminated by the prognostic score incorporating cg11676291_MORN1–age interaction (HR_{high vs. low} = 3.66, 95% CI: 2.40–5.60, p = 1.93 × 10⁻⁰⁹). By adding 24 significant gene–age interactions using a looser criterion, we significantly improved the area under the receiver operating characteristic curve (AUC) of the model at 3- and 5-year prognostic prediction (AUC_3-year = 0.80, AUC_5-year = 0.79, C-index = 0.75). Our study identified a significant interaction between cg11676291_MORN1 and age on OSCC survival, providing a potential therapeutic target for OSCC patients.

Exome sequencing identifies variants in infants with sacral agenesis

BACKGROUND

Sacral agenesis (SA) consists of partial or complete absence of the caudal end of the spine and often presents with additional birth defects. Several studies have examined gene variants for syndromic forms of SA, but only one has examined exomes of children with non-syndromic SA.

METHODS

Using buccal cell specimens from families of children with non-syndromic SA, exomes of 28 child-parent trios (eight with and 20 without a maternal diagnosis of pregestational diabetes) and two child-father duos (neither with diagnosis of maternal pregestational diabetes) were exome sequenced.

RESULTS

Three children had heterozygous missense variants in ID1 (Inhibitor of DNA Binding 1), with CADD scores >20 (top 1% of deleterious variants in the genome); two children inherited the variant from their fathers and one from the child's mother. Rare missense variants were also detected in PDZD2 (PDZ Domain Containing 2; N = 1) and SPTBN5 (Spectrin Beta, Non-erythrocytic 5; N = 2), two genes previously suggested to be associated with SA etiology. Examination of variants with autosomal recessive and X-linked recessive inheritance identified five and two missense variants, respectively. Compound heterozygous variants were identified in several genes. In addition, 12 de novo variants were identified, all in different genes in different children.

CONCLUSIONS

To our knowledge, this is the first study reporting a possible association between ID1 and non-syndromic SA. Although maternal pregestational diabetes has been strongly associated with SA, the missense variants in ID1 identified in two of three children were paternally inherited. These findings add to the knowledge of gene variants associated with non-syndromic SA and provide data for future studies.

Caudal Regression Syndrome

Caudal Regression Syndrome (CRS) or Caudal dysgenesis syndrome (CDS) is characterized by maldevelopment of the caudal half of the body with variable involvement of the gastrointestinal, genitourinary, skeletal, and nervous systems. CRS affects 1–3 newborn infants per 100,000 live births. The prevalence in infants of diabetic mothers is reported at 1 in 350 live births which includes all the variants. A related condition is sirenomelia sequence or mermaid syndrome or symmelia and is characterized by fusion of the legs and a variable combination of the other abnormalities. The Currarino triad is a related anomaly that includes anorectal atresia, coccygeal and partial sacral agenesis, and a pre-sacral lesion such as anterior meningocele, lipoma or dermoid cyst. A multidisciplinary management approach is needed that includes rehabilitative services, and patients need a staged surgical approach.

Caudal Regression Syndrome-A Review Focusing on Genetic Associations

Caudal regression syndrome (CRS) represents a spectrum of clinical phenotypes with varying degrees of malformation of the lower body with involvement of structures deriving from all 3 layers of the trilaminar embryo. We review areas of active investigation in the diagnosis, etiology, epidemiology, and treatment of the disease with a focus on underlying genetics. CRS pathobiology is complex and multifactorial with a significant contribution from environmental factors as evidenced in twin studies. Contemporary genomic and genetic investigations in both human primary tissue and murine in vitro and in vivo models implicate various genes associated with caudal differentiation and neural cell migration in embryogenesis. A large number of identified targets center around the metabolic regulation of retinoic acid and its derivatives. Dysregulation of retinoic acid homeostasis has been associated with abnormal embryonic cell migration, differentiation, and organogenesis with resulting malformations and agenesis in both a laboratory and a clinical setting. There appears to be a significant overlap in potential genetic targets with CRS and other developmental syndromes with similar presentations, such as VACTERL (vertebral defects, anal atresia, cardiac defects, tracheo-esophageal fistula, renal anomalies, and limb abnormalities) association. CRS represents a spectrum of caudal developmental abnormalities with treatment options limited to mild and moderate expressions of disease. Continued research is necessary to further clarify mechanisms of disease pathobiology and complex polygenetic and environmental interaction. Despite this, progress has been made in identifying genetic targets and downstream effectors contributing to preclinical and clinical progression.

Urine retention as the first presentation of congenital absence of the sacrum: A case report of a rare clinical phenomenon

RATIONALE

Congenital absence of either a part of or the entire sacrum is rare, and only a few such cases have been reported until now. Most cases showed vertebral, pelvic, neurological, and visceral abnormalities, and the cases were usually quite serious. Only in rare cases was there urine retention without other symptoms.

PATIENT CONCERNS

We describe the case of a 28-years-old man who presented with urine retention.

DIAGNOSES

Urodynamic study confirmed that he had urinary retention, and magnetic resonance imaging (MRI) showed the absence of the sacrum.

INTERVENTIONS

He was treated with electro-acupuncture and medications to improve nerve function.

OUTCOMES

His symptoms showed clear improvement.

LESSONS

Although this case is rare, it indicates that the spine and pelvis may need to be examined when unexplained urinary retention occurs.

How to Explore Fetal Sacral Agenesis Without Open Dysraphism: Key Prenatal Imaging and Clinical Implications

The estimated prevalence of fetal caudal dysgenesis is 1 per 100,000 births. The functional prognosis of sacral agenesis is dominated by the large spectrum of associated caudal malformations. Except for cases associated with hydrocephalus secondary to open spinal dysraphism or chromosomal anomalies, association with mental deficiency is rare. We propose a systematic prenatal approach to cases of fetal sacral agenesis based on 9 etiologic items: clinical context, type of sacral dysgenesis, associated spinal cord malformations, mobility of lower limbs, investigation of the presacral region, analysis of the gastrointestinal tract, analysis of the genitourinary tract, associated vertebral defects, and cytogenetic analysis.