Sensenbrenner syndrome (Cranioectodermal dysplasia): clinical and molecular analyses of 39 patients including two new patients

Sensenbrenner syndrome, also known as cranioectodermal dysplasia, is a rare multiple anomaly syndrome with distinctive craniofacial appearance, skeletal, ectodermal, connective tissue, renal, and liver anomalies. Dramatic advances with next-generation sequencing have expanded its phenotypic variability and molecular heterogeneity. We review 39 patients including two new patients, one with compound heterozygous novel mutations in WDR35 and a previously unreported multisutural craniosynostosis that may be a part of Sensenbrenner syndrome. In 14 of 25 (56.0%) patients pathogenic mutations have been identified in 4 different genes that regulate (intraflagellar) cilia transport. We compared Sensenbrenner syndrome to asphyxiating thoracic dystrophy-Jeune syndrome (ATD-JS) and other ciliopathies. Our analyses showed that the high anterior hairline, forehead bossing and dolichocephaly (accompanied by sagittal craniosynostosis in more than half of the patients) occur in almost all patients with Sensenbrenner syndrome. Metaphyseal dysplasia with narrow thorax, proximal limb shortness, and short fingers are typical of Sensenbrenner syndrome and ATD-JS. Respiratory complications have been reported in both syndromes, usually less severe with Sensenbrenner syndrome. Proposed diagnostic criteria for Sensenbrenner syndrome include the distinctive craniofacial appearance, ubiquitous brachydactyly and ectodermal anomalies, and sagittal craniosynostosis. Mild heart defects have been noted, but there have been no atrioventricular canal or heterotaxy defects that are common in Ellis-Van Creveld syndrome. We anticipate that the steady identification of molecularly defined patients may allow correlation of phenotype and genotype. Additional natural history data will improve genetic counseling and current guidelines.