Newly Identified t(2;17)(p15;q24.2) Chromosomal Translocation Is Associated with Dysgenetic Gonads and Multiple Somatic Anomalies.

ABSTRACT

Campomelic dysplasia (CD) is a skeletal dysplasia characterized by shortened and bowed long bones, airway instability, the potential for disorders of sexual differentiation (DSD), and Pierre Robin Sequence (PRS) with cleft palate, midface hypoplasia and laryngotrachemomalacia. CD is caused by alterations in the Sex-determining region of the Y chromosome (SRY)-related-box 9 (SOX9), which has important roles in tissue and sexual differentiation. The SOX9 gene and the enhancer regions of SOX9 are located at chromosome 17q24.3. We report a 6-year-old phenotypically female referred to our department because of precocious puberty. The patient was born with Tetralogy of Fallot (TOF) and PRS. Skeletal X-ray examination showed only 11 pairs of ribs and bilateral bowed radiuses. Endocrine evaluations showed that increased levels of serum testosterone, and chromosomal analysis revealed a 46, XY, t(2;17)(p15;q24.2) karyotype. The patient was diagnosed with peripheral precocious puberty caused by over-secretion of testosterone by gonadoblastoma originating from dysgenetic gonads with Y-chromosome-related DSD. Multiple somatic abnormalities and DSD indicated that the patient might have CD. Laparoscopy revealed bilateral dysgenetic gonads, and these were removed in the successive operation to prevent malignant transformation and virilization, caused by dysgenetic gonads with Y chromosomal materials. It is highly suggestive that the chromosomal translocation of 17q 24.2 may cause DSD and multiple somatic abnormalities, including CD, although the identified 17q breakpoint was located outside of known SOX9 enhancer regions. Thus, a hitherto unknown enhancer may be present at 17q24.2. This is the first reported case of CD with a translocation breakpoint at 17q24.2.