UNASSIGNED: Supernumerary ribs are very rare. They may occur at any level of the spine. We present here a case of an unusual localization of an extra rib that has not been previously described in the literature.
METHODS: A 4-year-old girl, with no medical history, presented with a congenital deformity in the sternal region mimicking a tail. The tail-like structure had a bony axis and was covered by normal skin and hairs. A computed tomography of the chest demonstrated that this structure was an abnormal bone articulated with the the sternum. For cosmetic purposes, we have decided to resect the malformation. On histopathological examination, it was a supernumerary rib.
UNASSIGNED: A review of the literature reveals a global incidence of cervical ribs ranging from 0.04 % up to 4.5 %, intrathoracic ribs in about 50 cases to date and very few reports on supernumerary ribs in the lumbar and sacral region. We were unable to find any similar cases of supernumerary ribs in the sternum.
CONCLUSIONS: Supernumerary ribs are rare and benign congenital anomalies. This case report describes an unusual localization of an extra rib in the sternum mimicking a tail.

Williams-Beuren syndrome is a rare multisystemic genetic disorder with an incidence of 1 in 7,500 live births. Because these children often have scoliosis, they undergo routine radiographic examinations of the spine. During these examinations we have found many children with supernumerary lumbar ribs arising from the first lumbar vertebra, often associated with lumbosacral transitional vertebrae.
To describe the incidence of supernumerary ribs and transitional vertebrae in children with Williams-Beuren syndrome and compare it to the incidence in a general population. Our hypothesis is that these findings are common, but they have not been described in the literature concerning Williams-Beuren syndrome.
From January 2015 to October 2021, 308 patients (138 male) with Williams-Beuren syndrome were treated at our hospital. Of these, 106 (47 male) underwent diagnostic imaging, mostly for suspected scoliosis. Panoramic radiographs of the whole spine were performed in 88 patients and radiographs of regions of the spine, chest radiographs, CT, MRI or fluoroscopy in 18 patients. We retrospectively analysed the images concerning the number of ribs and vertebrae. We correlated the frequency of lumbar ribs and transitional vertebrae in comparison to a general population as described in the literature.
After exclusions for insufficient imaging, we analysed imaging in 91 patients. Of these, 67 patients (73.6%) had 13 ribs, of which 85% were located on both sides, 9% on the right and 6% on the left side. Of the 67 patients with supernumerary lumbar ribs, 38 (57%) also had transitional vertebrae.
Supernumerary lumbar ribs arising from the first lumbar vertebra, often accompanied by lumbosacral transitional vertebrae, are common in children with Williams-Beuren syndrome.

RIPPLY2 is an essential part of the formation of somite patterning during embryogenesis and in establishment of rostro-caudal polarity. Here, we describe three individuals from two families with compound-heterozygous variants in RIPPLY2 (NM_001009994.2): c.238A > T, p.(Arg80*) and c.240-4 T > G, p.(?), in two 15 and 20-year-old sisters, and a homozygous nonsense variant, c.238A > T, p.(Arg80*), in an 8 year old boy. All patients had multiple vertebral body malformations in the cervical and thoracic region, small or absent rib involvement, myelopathies, and common clinical features of SCDO6 including scoliosis, mild facial asymmetry, spinal spasticity and hemivertebrae. The nonsense variant can be classified as likely pathogenic based on the ACMG criteria while the splice variants must be classified as a variant of unknown significance. With this report on two further families, we confirm RIPPLY2 as the gene for SCDO6 and broaden the phenotype by adding myelopathy with or without spinal canal stenosis and spinal spasticity to the symptom spectrum.

UNASSIGNED: Since the gap between two atretic segments of oesophagus is a critical determinant of prognosis for oesophageal atresia/tracheoesophageal fistula (EA/TEF), the search for a surrogate non-invasive pre-operative marker of long gap atresia continues.
UNASSIGNED: The purpose of the study was to compare the presence of normal and supernumerary ribs with length of EA and survival rates.
UNASSIGNED: A prospective observational study was conducted at a tertiary care referral neonatal intensive care unit in North Karnataka, India, from January 2016 to June 2019.
UNASSIGNED: Amongst babies with EA/TEF, pre-operative radiograph helped determine the number of ribs, and babies were divided into two groups; Group I: babies with 12 ribs and Group II: babies with supernumerary ribs.
UNASSIGNED: Nominal variables were expressed as percentage and continuous variables as mean standard deviation. MedCalc software was used to compare proportions and means. A P < 0.05 was considered statistically significant.
UNASSIGNED: Of the 61 cases, 51 were operated. Long gap EA was predominantly seen amongst babies in Group II (40% in Group II vs. 27% in Group I, P= 0.424). Survival rates by percentage were lower in babies in Group II (60% in Group II vs. 80% in Group I, P= 0.188). Both the above findings were proven statistically insignificant. The overall survival rate amongst the study population was 78.4% (39/51).
UNASSIGNED: Supernumerary ribs were associated with a higher occurrence of long gap EA and lower survival rates, though statistically insignificant. Multicentre collaboration may provide significant input for strengthening or refuting the above hypothesis.

The clinical and radiological spectrum of spondylocostal dysostosis syndromes encompasses distinctive costo-vertebral anomalies. RIPPLY2 biallelic pathogenic variants were described in two distinct cervical spine malformation syndromes: Klippel-Feil syndrome and posterior cervical spine malformation. RIPPLY2 is involved in the determination of rostro-caudal polarity and somite patterning during development. To date, only four cases have been reported. The current report aims at further delineating the posterior malformation in three new patients. Three patients from two unrelated families underwent clinical and radiological examination through X-ray, 3D computed tomography and brain magnetic resonance imaging. After informed consent was obtained, family-based whole exome sequencing (WES) was performed. Complex vertebral segmentation defects in the cervico-thoracic spine were observed in all patients. WES led to the identification of the homozygous splicing variant c.240-4T>G in all subjects. This variant is predicted to result in aberrant splicing of Exon 4. The current report highlights a subtype of cervical spine malformation with major atlo-axoidal malformation compromising spinal cord integrity. This distinctive mutation-specific pattern of malformation differs from Klippel-Feil syndrome and broadens the current classification, defining a sub-type of RIPPLY2-related skeletal disorder. Of note, the phenotype of one patient overlaps with oculo-auriculo-vertebral spectrum disorder.

Evaluation of the skeleton in laboratory animals is a standard component of developmental toxicology testing. Standard methods of performing the evaluation have been established, and modification of the evaluation using imaging technologies is under development. The embryology of the rodent, rabbit, and primate skeleton has been characterized in detail and summarized herein. The rich literature on variations and malformations in skeletal development that can occur in the offspring of normal animals and animals exposed to test articles in toxicology studies is reviewed. These perturbations of skeletal development include ossification delays, alterations in number, shape, and size of ossification centers, and alterations in numbers of ribs and vertebrae. Because the skeleton is undergoing developmental changes at the time fetuses are evaluated in most study designs, transient delays in development can produce apparent findings of abnormal skeletal structure. The determination of whether a finding represents a permanent change in embryo development with adverse consequences for the organism is important in study interpretation. Knowledge of embryological processes and schedules can assist in interpretation of skeletal findings.