Prenatal diagnosis of hemivertebrae—A likely association with 7q deletion

Prenatal diagnosis and pregnancy outcomes in fetuses with vertebral abnormalities

OBJECTIVE

To investigate the genetic risk and pregnancy outcomes of fetuses who had the sonographic diagnosis of vertebral abnormalities (VA).

METHODS

Fifty-two fetuses with sonographically detected VA (excluding neural tube defects) were included in the study. Data on prenatal ultrasound scan, prenatal genetic testing by amniocentesis, and pregnancy outcomes were collected and reviewed.

RESULTS

Four types of VA were identified among 52 fetuses: butterfly vertebrae (26.9%, 14/52), hemivertebrae (59.6%, 31/52), hemivertebrae combined with butterfly vertebrae (9.6%, 5/52), and block vertebrae (3.9%, 2/52). Of the 52 fetuses, 33 presented VA as the sole sonographic anomaly, while the remaining 19 had associated anomalies. The positive rate of prenatal diagnosis for fetuses with VA was 19.2% (10/52). Chromosomal analysis, including karyotyping and chromosomal microarray analysis (CMA), detected one case of mosaic trisomy 9 and six cases of (likely) pathogenic copy number variants (CNVs). Whole exome sequencing (WES) identified four likely pathogenic variants in three cases with negative CMA results, specifically c.5110-1G > A in FLNB, c.8366G > A in KMT2D, and c.1275_1283dup as well as c.870 + 2T > C in DLL3. Among the 10 cases with diagnostic genetic testing results, seven fetuses exhibited isolated VA. There was no significant difference in the diagnostic rates between the isolated VA group (21.2%, 7/33) and the non-isolated VA group (15.8%, 3/19) (odds ratio [OR] 0.696, 95% confidence interval [CI] 0.157-3.087, p = 0.910). However, the live birth rate was significantly higher in the isolated VA group (71.9%, 23/32) compared to the non-isolated VA group (38.9%, 7/18) (OR 4.016, 95% CI 1.184-13.622, p = 0.022). Among the 30 live birth cases, two underwent spinal surgery and another two were identified with additional abnormalities. Following appropriate interventions, no apparent abnormalities were observed in the growth and development of 30 live birth cases.

CONCLUSION

Invasive prenatal diagnosis is recommended for all fetuses diagnosed with VA, regardless of whether associated anomalies are present. WES can enhance the diagnostic yield for fetuses with negative CMA results. Fetuses with isolated VA can have favorable pregnancy outcomes when genetic testing results are negative. However, long-term follow-up remains necessary for the assessment of the prognosis of these fetuses.

Umbilical cord-derived mesenchymal stem cells implantation on Hemivertebra defect with three-year follow-up: Biological approach in congenital scoliosis treatment - A case report

Introduction and importance

Congenital scoliosis is abnormal vertebral column growth and development during embryogenesis. The most common type of congenital scoliosis is failure of growth which is called as hemivertebra. However, the recent surgical treatment of hemivertebra has several complications especially in young patient. The mesenchymal stem cells (MSCs) have been used to treat several bone problems including bone defect and may be have potential to treat the defect in hemiverterbra. We reported a hemivertebra treated by umbilical cord-derived MSCs (UC-MSCs).

Case presentation

A two-year-old boy presented with scoliosis deformity. The mother noticed the patient's deformity when he was 10th month of age as he learned to stand and progressed since then. There were no growth and development problems. On physical examination, the patient appeared to have scoliosis at lumbar level with bending to the right and asymmetry of waist fold with left shoulder depression. Based on X-ray and CT-Scan investigations, the patient was diagnosed with single fully segmented hemivertebra at 3rd lumbar level. 20 × 10⁶ UC-MSCs were implanted into the bone defect of hemivertebra.

Clinical discussion

At three-year follow-up, the X-ray and MRI investigations showed a decrease of Cobb angle and increase of hemivertebra ratio. These findings may be due to improvement of the bone defect, which is consistent with several studies that MSCs have abilities to promote bone formation by maintaining the osteoblast cells and improving vascularization.

Conclusion

We found that MSCs therapy for hemivertebra represent a potential therapy to correct scoliosis curvature and prevent further curvature. Further clinical studies are required to investigate the efficacy of this therapy in hemivertebra.

•

Hemivertebrae is due to the failure of development of vertebrae.

•

Mesenchymal stem cells induce new bone formation.

•

Symmetrical growth of the spine is required for prevent spinal deformity.

•

Regenerative therapy using mesenchymal stem cells as treatment strategy for hemivertebra

•

Implantation of mesenchymal stem cells in hemivertebra is safe procedure.

Genetics of non-isolated hemivertebra: A systematic review of fetal, neonatal, and infant cases

Hemivertebra is a congenital vertebral malformation caused by unilateral failure of formation during embryogenesis that may be associated with additional abnormalities. A systematic review was conducted to investigate genetic etiologies of non-isolated hemivertebra identified in the fetal, neonatal, and infant periods using PubMed, Cochrane database, Ovid Medline, and ClinicalTrials.gov from inception through May 2022 (PROSPERO ID CRD42021229576). The Human Phenotype Ontology database was accessed May 2022. Studies were deemed eligible for inclusion if they addressed non-isolated hemivertebra or genetic causes of non-isolated hemivertebra identified in the fetal, neonatal, or infant periods. Cases diagnosed clinically without molecular confirmation were included. Systematic review identified 23 cases of non-isolated hemivertebra with karyotypic abnormalities, 2 cases due to microdeletions, 59 cases attributed to single gene disorders, 18 syndromic cases without known genetic etiology, and 14 cases without a known syndromic association. The Human Phenotype Ontology search identified 49 genes associated with hemivertebra. Non-isolated hemivertebra is associated with a diverse spectrum of cytogenetic abnormalities and single gene disorders. Genetic syndromes were notably common. Frequently affected organ systems include musculoskeletal, cardiovascular, central nervous system, genitourinary, gastrointestinal, and facial dysmorphisms. When non-isolated hemivertebra is identified on prenatal ultrasound, the fetus must be assessed for associated anomalies and genetic counseling is recommended.

Ontogeny of morphological variations in the vertebral column: Prevalence and bony variability in young Spanish children

Pre- and postnatal development and variability in discrete vertebral traits have been poorly described in embryonic studies. Numerous authors have reported that these variations are observable only from adolescence; scientific publications on the vertebrae of fetuses and infants are scarce. Thus, the aims of this study were to (1) describe the ontogeny and variability of anatomical variations in the vertebral column of a Spanish infant population and (2) analyze the frequency and relationship between sex, age, and intertrait variables. A total of 4728 vertebrae from 197 skeletons were studied. The age at death ranged from 22 intrauterine weeks to 8 years. Twenty morphological traits related to vertebral column development were analyzed. A descriptive statistical analysis was performed, and the chi-square test was used to measure the relationship between sex, age, and intertrait variables. We observed that 88.32% of skeletons expressed discrete traits along the spine. In fetuses, the double transverse foramen and unclosed transverse process of the axis were the most prevalent traits. In infants older than one year, the appearance of the L5 cleft neural arch, unclosed transverse process of the atlas, and craniocaudal shifts were frequent. A significant result was found between sex and the unclosed transverse process in the axis. The intertrait relationship was significant for all traits that shared the same embryonic structure. Morphological variations became visible following the appearance of ossification centers during the pre- and postnatal periods, and their etiology was associated with embryonic development.

Prenatal ultrasound-assisted identification of multiple malformations caused by a deletion in the long-arm end of chromosome 7 and review of the literature

Clinical cases of chromosome 7 long-arm end deletion are rare. Generally, 7q terminal deletion syndrome results in complex clinical phenotypes, such as microcephaly, growth and development retardation, holoprosencephaly, and sacral hypoplasia. Herein, we report the genetic and clinical features of a fetus with multiple malformations observed by prenatal ultrasound. The results showed that there was a large fragment deletion of approximately 27.7 Mb in 7q32.3-qter. The induced fetus showed facial abnormalities of cleft lip and palate, and some organ structural abnormalities (such as diaphragmatic hernia and polycystic renal dysplasia) were observed by autopsy and pathology. To provide more reliable information for disease diagnosis and genetic counseling, we reviewed and analyzed the reported cases of isolated 7q terminal syndrome.

Retrospective analysis of fetal vertebral defects: Associated anomalies, etiologies, and outcome

Our objectives were to describe fetal cases of vertebral defects (VD), assess the diagnostic yield of fetal chromosomal analysis for VD and determine which investigations should be performed when evaluating fetal VD. We performed a retrospective chart review for fetuses with VD seen between 2006 and 2015. Cases were identified from CHU Sainte-Justine's prenatal clinic visits, postmortem fetal skeletal surveys, and medical records. Cases with neural tube defects were excluded. Sixty-six fetuses with VD were identified at a mean gestational age of 20 weeks. Forty-seven (71.2%) had associated antenatal anomalies, most commonly genitourinary, skeletal/limb, and cardiac anomalies. Thirteen mothers (19.7%) had pregestational diabetes (95% CI [10.1%-29.3%]). Fifty-three cases had chromosomal analysis. Three had abnormal results (5.6%): trisomy 13, trisomy 22, and 9q33.1q34.11 deletion. Thirty-four (51.5%) pregnancies were terminated, one led to intrauterine fetal demise and 31 (46.9%) continued to term. Of 27 children who survived the neonatal period, 21 had congenital scoliosis and 3 had spondylocostal dysostosis. Seven had developmental delay. In conclusion, prenatal evaluation of fetuses with VD should include detailed morphological assessment (including fetal echocardiogram), maternal diabetes screening, and chromosomal microarray if non-isolated. Our findings provide guidance about management and counseling after a diagnosis of fetal VD.

The oldest record of aquatic amniote congenital scoliosis

We report the first occurrence of congenital scoliosis in an early Permian aquatic parareptile, Stereosternum tumidum from Paraná state, Brazil. The spine malformation is caused by a congenital hemivertebra. These observations give insight into the biomechanical aspects of underwater locomotion in an axial skeleton-compromised aquatic amniote. This is the oldest record of a hemivertebra in an aquatic animal.