Bifid ribs and unusual vertebral anomalies diagnosed in an anatomical specimen. Gorlin syndrome?

Bifurcated rib with vertebral defects - A rare anatomical variant: Case report with literature review

•

Bifid ribs with vertebral defects and no other clinical manifestation is not a sign of any medical or surgical intervention.

•

Such patients should be comprehensively screened by multidisciplinary team to exclude other differentials, especially Gorlin syndrome.

•

Regular follow-ups should always be recommended to monitor early onset of nevoid basal cell carcinoma.

•

Patient and family education about the possibility of Gorlin syndrome in such situations should be done.

Introduction

Bifurcated ribs are a neuroskeletal anomaly which are incidentally discovered on chest X-ray. It is a developmental disorder where sternal end of a rib is split into two, commonly found in males, on the right side and unilaterally not associated with a vertebral defect.

Presentation of case

In this report we discuss a case of a 17-year-old girl with a left bifid rib alongside a segmental defect of the vertebra.

Discussion

Bifurcated ribs usually occur in isolation or with other rib abnormalities associated with vertebral defects. Most cases are asymptomatic or found at post-mortem. Gorlin Syndrome is a condition where both these anatomical defects form a part of its criteria.

Conclusion

With barely any data on significance of bifid rib with vertebral defects and no conclusive exclusion of Gorlin Syndrome, close monitoring coupled with regular follow-ups in such patients is the likely plan of treatment. In addition, genetic testing for susceptible genes should be strongly considered.

The genetic landscape and clinical implications of vertebral anomalies in VACTERL association

VACTERL association is a condition comprising multisystem congenital malformations, causing severe physical disability in affected individuals. It is typically defined by the concurrence of at least three of the following component features: vertebral anomalies (V), anal atresia (A), cardiac malformations (C), tracheo-oesophageal fistula (TE), renal dysplasia (R) and limb abnormalities (L). Vertebral anomaly is one of the most important and common defects that has been reported in approximately 60–95% of all VACTERL patients. Recent breakthroughs have suggested that genetic factors play an important role in VACTERL association, especially in those with vertebral phenotypes. In this review, we summarised the genetic studies of the VACTERL association, especially focusing on the genetic aetiology of patients with vertebral anomalies. Furthermore, genetic reports of other syndromes with vertebral phenotypes overlapping with VACTERL association are also included. We aim to provide a further understanding of the genetic aetiology and a better evidence for genetic diagnosis of the association and vertebral anomalies.

Additional circular intercostal space created by bifurcation of the left 3rd rib and its costal cartilage: a case report

INTRODUCTION

In the thorax there are normally 11 pairs of intercostal spaces: the spaces between adjacent ribs. The intercostal spaces contain intercostal muscles, intercostal nerves and vessels.

CASE PRESENTATION

During a routine dissection for undergraduate medical students, we observed a variation involving the left 3rd rib and 3rd costal cartilage in the cadaver of a man of Indian ethnicity aged about 65 years. The left 3rd rib and its costal cartilage were bifurcated at their costochondral junction enclosing a small circular additional intercostal space. Muscle tissue covered by deep fascia was present in this circular intercostal space. The muscle in the circular intercostal space received its nerve supply from a branch of the 2nd intercostal nerve.

CONCLUSIONS

Knowledge of such variations is helpful to surgeons operating on the anterior thoracic wall involving ribs and intercostal spaces. Knowing the possibility of the presence of an additional space between normal intercostal spaces can guide a surgeon through to a successful surgery.

Chondro-manubrial deformity and bifid rib, rare variations seen in pectus carinatum: a radiological finding

Pectus carinatum or protrusion deformity of chest wall is less frequently occurring anterior chest wall deformity when compared to pectus excavatum. It may be classified as type 1 or chondro-gladiolar and type 2 or chondro-manubrial deformity. Other variations seen are symmetrical and asymmetrical pectus carinatum. Here we present two unique case reports, one with chondro-manubrial deformity (Currarino-Silverman syndrome) and other with asymmetrical pectus carinatum having bifid rib which are some of the rare variations seen in pectus carinatum found during Computerized tomographic examination. Currarino-Silverman syndrome is a type 2 pectus carinatum, a rare deformity with chondro-manubrial involvement and usually associated congenital heart diseases. Early fusion of sternal plates is one of the known theories in producing this deformity. On the other hand, asymmetrical pectus deformity are usually seen due to imbalance or abnormality in growth plates of costal cartilages leading to forked rib or bifid rib, which are accidently seen on radiological examination. To conclude, our reports would help in differential diagnosis from frequently occurring conditions affecting chest like chondro-gladiolar deformity, pectus excavatum, chest wall tumours, rib fractures and intra thoracic ribs.

Rab23 plays a role in the pathophysiology of mesangial cells--a proteomic analysis

Rab23, a novel member of the Rab family of small GTPases, has recently been identified in mesangial cells (MCs). Although Rab23 levels in MCs are associated with glomerular nephropathies, the exact physiological and pathological roles of Rab23 in MCs are unknown. In the present study, its roles in MCs were explored by performing proteomics and systems biology analyses in MCs after knockdown or overexpression of Rab23. Knockdown of Rab23 was achieved by transfecting MCs with a plasmid expressing short hairpin RNA against Rab23, while overexpression of Rab23 was accomplished by transfection with the wild-type, dominant negative, and constitutively active Rab23 gene constructs. The effects of different levels of Rab23 activity on proteome of various biological pathways were investigated. Gel-based proteomic approaches and systems biology tools, respectively, were used to identify the Rab23-regulated proteins and the functional pathways. Proteomic analysis revealed the potential roles for Rab23 in multiple processes, including G-protein signal transduction, transcription modulation, RNA stabilization, protein synthesis and degradation, cytoskeleton reorganization, anti-oxidation and detoxification, circadian rhythm regulation and phagocytosis. Bioinformatics analyses showed that Rab23 impacts on multiple biological networks in MCs. These data may shed light on the roles of Rab23 in mesangiopathy or MC damage.

Bifid rib: anatomical considerations in three cases

The present study involved a detailed investigation of 3 cases of bifid rib, focusing on anatomical features, and classified them into 2 types. The bifid ribs were in the right fourth rib of all 3 male cadavers. The upper intercostal spaces of the fourth bifid rib were considerably narrowed, whereas the lower intercostal spaces were widened. Although the size and shape of the bifid space between the upper and lower divisions of the bifid rib were different, the intercostal muscles were present in the bifid space in all cases. The third anterior intercostal artery from the internal thoracic artery supplied the bifid space in all cases. In 2 cases, the fourth intercostal nerve ran along the inferior margin of the fourth bifid rib and innervated the muscles of the bifid space. In the third case, there was another branch from the third intercostal nerve supplying the muscles of the bifid space as well as the fourth intercostal nerve. The bifid ribs are associated with other diseases or develop accidentally or sporadically. Knowledge of this malformation is needed for the differential diagnosis with other diseases, such as a chest wall tumor or costal fracture.