Exploring copy number variants in deceased fetuses and neonates with abnormal vertebral patterns and cervical ribs.

BACKGROUND: Cervical patterning abnormalities are rare in the general population, but one variant, cervical ribs, is particularly common in deceased fetuses and neonates. The discrepancy between the incidence in the general population and early mortality is likely due to indirect selection against cervical ribs. The cause for the co-occurrence of cervical ribs and adverse outcome remains unidentified. Copy number variations resulting in gain or loss of specific genes involved in development and patterning could play a causative role. METHODS: Radiographs of 374 deceased fetuses and infants, including terminations of pregnancies, stillbirths and neonatal deaths, were assessed. Copy number profiles of 265 patients were determined using single nucleotide polymorphism array. RESULTS: 274/374 patients (73.3%) had an abnormal vertebral pattern, which was associated with congenital abnormalities. Cervical ribs were present in 188/374 (50.3%) and were more common in stillbirths (69/128 [53.9%]) and terminations of pregnancies (101/188 [53.7%]), compared to live births (18/58, 31.0%). Large (likely) deleterious copy number variants and aneuploidies were prevalent in these patients. None of the rare copy number variants were recurrent or overlapped with candidate genes for vertebral patterning. CONCLUSIONS: The large variety of copy number variants in deceased fetuses and neonates with similar abnormalities of the vertebral pattern probably reflects the etiological heterogeneity of vertebral patterning abnormalities. This genetic heterogeneity corresponds with the hypothesis that cervical ribs can be regarded as a sign of disruption of critical, highly interactive stages of embryogenesis. The vertebral pattern can probably provide valuable information regarding fetal and neonatal outcome.

Cervical ribs and other abnormalities of the vertebral pattern in children with esophageal atresia and anorectal malformations.

BACKGROUND: In mammals the vertebral column has a constant pattern, particularly in the cervical region, which is likely the result of stabilizing selection. The prevalence of cervical ribs and extended vertebral pattern abnormalities is increased in deceased fetuses and neonates and associated with structural and chromosomal anomalies. The hypothesized close interaction between vertebral patterning and organogenesis in early embryogenesis could be studied in children with esophageal atresia and anorectal malformations by evaluating the radiographs of the vertebral column and the type and number of associated anomalies METHODS: The vertebral pattern of 367 children diagnosed with an esophageal atresia (n = 135), anorectal malformation (n = 215), or both (n = 17) was assessed on radiographs. RESULTS: The vertebral pattern was abnormal in 170/202 (84.2%) children in whom this could be assessed, and cervical ribs were present in 147/335 (43.9%). Extended vertebral pattern abnormalities became more frequent with an increasing number of associated structural abnormalities. Cervical ribs were particularly common in children with chromosomal and genetic abnormalities (18/20, 90.0%). CONCLUSIONS: Cervical ribs are frequent and abnormal vertebral patterns are more extended in the presence of associated anomalies. These findings support the hypothesized selection against vertebral patterning variations and emphasize the relevance of assessment of the vertebral pattern.

Differences in Origin and Outcome of Intra-Abdominal Cysts in Male and Female Fetuses.

OBJECTIVE: To investigate the origin and outcome in a cohort of male and female fetuses with intra-abdominal cysts, in order to provide recommendations on management and to improve prenatal counselling. METHODS: From 2002 to 2016, intra-abdominal cysts were detected by ultrasound in 158 fetuses. Cases with an umbilical vein varix were excluded. Fetal, neonatal, and maternal characteristics were retrieved from electronic patient files. RESULTS: In female fetuses (n = 114), intra-abdominal cysts were diagnosed at a later gestational age compared with male fetuses (n = 44) (median 32.0 vs. 21.5 weeks, p < 0.001). The maximum prenatal cyst diameter was larger in female fetuses (median 35 vs. 17 mm, p < 0.001). Associated anomalies were less frequent in females (n = 15, 13.2%) compared with males (n = 15, 34.1%). In females (n = 114), most cysts were of ovarian origin (n = 81, 71.1%). Surgery was performed in 30 (26.3%) female and 15 (34.1%) male neonates (p = 0.33). Anorectal malformations were present in 6 cases and often not recognized prenatally. CONCLUSIONS: The differences in the origin of intra-abdominal cysts between male and female fetuses, resulting in differences in prenatal presentation and postnatal outcome should be taken into account in prenatal counseling within a multidisciplinary team. Evaluation of the fetal perianal muscular complex is indicated.

Increased prevalence of abnormal vertebral patterning in fetuses and neonates with trisomy 21.

PURPOSE: To assess the prevalence of an abnormal number of ribs in a cohort of fetuses and neonates with trisomy 21 and compare this with a subgroup of fetuses without anomalies. MATERIALS AND METHODS: Radiographs of 67 deceased fetuses, neonates, and infants that were diagnosed with trisomy 21 were reviewed. Terminations of pregnancy were included. The control group was composed of 107 deceased fetuses, neonates, and infants without known chromosomal abnormalities, structural malformations, infections or placental pathology. Cases in which the number of thoracic ribs or presence of cervical ribs could not be reliably assessed were excluded. The literature concerning vertebral patterning in trisomy 21 cases and healthy subjects was reviewed. RESULTS: Absent or rudimentary 12th thoracic ribs were found in 26/54 (48.1%) cases with trisomy 21 and cervical ribs were present in 27/47 (57.4%) cases. This prevalence was significantly higher compared to controls (28/100, 28.0%, Χ2(1) = 6.252, p = .012 and 28/97, 28.9%, Χ2(1) = 10.955, p < .001, respectively). CONCLUSIONS: Rudimentary or absent 12th thoracic ribs and cervical ribs are significantly more prevalent in deceased fetuses and infants with trisomy 21.