[Klippel-Feil autosomal dominant syndrome: A malformation of vertebral segmentation]

Klippel-Feil syndrome is a highly heterogeneous complex skeletal disorder characterized by the con genital fusion of two or more cervical vertebrae. The classic clinical triad consists of a short neck, low hairline, and neck movements limitation. The associated mutations are located in the loci of the GDF3 gene (chromosome 12p13.31), GDF6 (chromosome 8q22.1), and MEOX1 (chromosome 17q21.31).

To describe the clinical-radiological findings and pedigree of a patient with Klippel-Feil syndrome.

A 5-year-old patient with short neck, low posterior hairline, and limitation of lateral movements. The cervical flexion and extension radiographs showed fusion blocks between C1-2-3, C4-5, and C6-7. The chest CT scan showed multiple hemivertebrae in the upper third of the thoracic vertebrae corresponding to ribs I-IV. The karyotype was normal, 46, XX. Reduced penetrance was present in five of the family members. The fusion of C2-3 was present in four members and one individual had low fusion in C5-6. Three of the five affected individuals had a fusion between the capitate and the hamate bone.

The malformation of congenital vertebral segmentation is a case of interest since it is an uncommon diagnosis in the pediatric age and whose clinical suspicion can be generated from the clinical examination, radiological study com plemented with the pedigree interpretation in Mendelian inheritance disorders, allowing to provide opportunely genetic counseling to the family.