Clinical Guidance

To date, approximately 100 individuals (fetuses included) with a pathogenic variant in SOX9 have been identified; the data are scattered across many case reports and a few small series [, , , , , , , , , , , , ]. The following description of the phenotypic features associated with this condition is based on these reports. Campomelic dysplasia (CD) is sometimes identified on prenatal ultrasound examination but may escape detection until after birth if the limbs are not bowed. Many newborns with CD die shortly after birth secondary to respiratory insufficiency. In comparison with other lethal skeletal dysplasias, the cause of death in CD is not related to thoracic cage hypoplasia but rather to airway instability (tracheobronchomalacia) or cervical spine instability.

Penetrance

Pathogenic variants in the SOX9 coding region are completely penetrant. Breakpoints at long distance from SOX9 may not be completely penetrant.

Diagnostic Criteria

No consensus clinical diagnostic criteria for campomelic dysplasia (CD) have been published. The diagnosis of CD (derived from the Greek for "bent limb") can usually be clearly established based on clinical and radiographic findings. Although no single clinical feature is obligatory, the radiographic features are consistent and are the most reliable diagnostic clues.

Suggestive Findings

CD should be suspected in individuals with the following clinical and radiographic features.

Clinical features

Management Guidelines

Evaluations Following Initial Diagnosis To establish the extent of disease and needs in an individual diagnosed with campomelic dysplasia (CD), the evaluations summarized (if not performed as part of the evaluation that led to the diagnosis) are recommended for those infants surviving the neonatal period. Table 3. Recommended Evaluations Following Initial Diagnosis in Individuals with Campomelic Dysplasia

Surveillance Guidelines

Table 5.

Recommended Surveillance for Individuals with Campomelic Dysplasia

System/Concern | Evaluation | Frequency

Kyphoscoliosis

| Clinical radiographic assessment for spinal curvature | Annually in long-term survivors

Source: GeneReviews — "Campomelic Dysplasia"