Clinical Guidance

Spondylocostal dysostosis (SCDO), defined radiographically as multiple segmentation defects of the vertebrae that is usually generalized throughout the spine, is characterized clinically by a short trunk in proportion to height, short neck, and non-progressive mild scoliosis in most affected individuals. To date, nearly 100 individuals have been identified and/or reported with SCDO and biallelic pathogenic variants in one of the genes listed in . The following description of the phenotypic features associated with this condition is based on the cited reports. Skeletal. Multiple segmentation defects of the vertebrae, which is usually generalized throughout the spine, results in:

Diagnostic Criteria

Suggestive Findings

Spondylocostal dysostosis (SCDO) should be suspected in individuals with the following radiographic features and family history:

• Multiple segmentation defects of the vertebrae (M-SDV) most evident on anteroposterior radiograph of the whole spine. Abnormal segmentation of at least ten contiguous vertebrae. In the affected fetus or young child each vertebra is round or ovoid with smooth boundaries; the appearance of the vertebral column has been referred to as the "pebble beach" sign , especially in DLL3-related SCDO. As ossification proceeds after mid- to late childhood, the "pebble beach" appearance gives way to multiple irregularly shaped vertebral bodies and hemivertebrae that may be difficult to distinguish individually on plain x-ray.

Management Guidelines

No clinical practice guidelines for autosomal recessive spondylocostal dysostosis (SCDO) have been published. Evaluations Following Initial Diagnosis To establish the extent of disease and needs in an individual diagnosed with autosomal recessive SCDO, the evaluations summarized (if not performed as part of the evaluation that led to the diagnosis) are recommended. Table 3. Autosomal Recessive Spondylocostal Dysostosis: Recommended Evaluations Following Initial Diagnosis

Surveillance Guidelines

To monitor existing manifestations, the individual's response to supportive care, and the emergence of new manifestations, the evaluations summarized in are recommended. Table 5. Autosomal Recessive Spondylocostal Dysostosis: Recommended Surveillance