Campomelic Dysplasia

Excerpt

Clinical characteristics: Campomelic dysplasia (CD) is a skeletal dysplasia characterized by distinctive facies, Pierre Robin sequence with cleft palate, shortening and bowing of long bones, and clubfeet. Other findings include laryngotracheomalacia with respiratory compromise and ambiguous genitalia or normal female external genitalia in most individuals with a 46,XY karyotype. Many affected infants die in the neonatal period; additional findings identified in long-term survivors include short stature, cervical spine instability with cord compression, progressive scoliosis, and hearing impairment.

Diagnosis/testing: The diagnosis of CD is usually based on clinical and radiographic findings. Identification of a heterozygous pathogenic variant in SOX9 by molecular genetic testing can confirm the diagnosis if clinical and radiographic features are inconclusive.

Management: Treatment of manifestations: Care of children with cleft palate by a craniofacial team using routine measures; in persons with a 46,XY karyotype and undermasculinization of the genitalia, the gonads should be removed because of the increased risk for gonadoblastoma; care of hip subluxation and clubfeet using standard protocols; hearing aids for those with hearing impairment; surgery as needed for cervical vertebral instability and progressive cervicothoracic kyphoscoliosis that compromises lung function.

Prevention of secondary complications: If a cervical spine abnormality is identified, special care should be exercised for any surgical procedure.

Surveillance: Annual monitoring of spinal curvature.

Genetic counseling: CD is inherited in an autosomal dominant manner. To date, most probands have CD as the result of a de novo pathogenic variant in SOX9; thus, parents of probands are not typically affected. However, a few adults have been diagnosed with CD following the birth of an affected child. Recurrence in sibs has occurred and somatic and germline mosaicism have been reported. Prenatal testing for a pregnancy at increased risk is possible if the pathogenic variant in the family is known.