A patient presents with kinky, sparse hair, osteosclerosis at the base of the skull, brittle nails, and enamel hypomaturation. Which syndrome does this represent?

Correct answer: A. Cranioectodermal dysplasia

• A. CORRECT. CRANIOECTODERMAL DYSPLASIA (Sensenbrenner syndrome) is a ciliopathy that combines a CRANIAL abnormality — sagittal craniosynostosis with a dolichocephalic head and sclerotic skull base — with widespread ECTODERMAL defects: fine, sparse, slow-growing 'kinky' hair, thin brittle dysplastic nails, and dental anomalies including microdontia, hypodontia, taurodontism and enamel hypoplasia/hypomaturation. Renal and hepatic fibrosis may follow.
• B. Klinefelter syndrome (47,XXY) presents with tall stature, gynecomastia, hypogonadism and infertility. Its dental association is TAURODONTISM, but there is no kinky hair, brittle nails or skull-base osteosclerosis.
• C. Papillon-Lefevre syndrome combines palmoplantar hyperkeratosis with severe early-onset periodontitis destroying both dentitions; hair, nails and enamel are not the primary findings.
• D. Rubinstein-Taybi syndrome features broad thumbs and great toes, a beaked nose, intellectual disability, and talon cusps — but not the hair-nail-skull triad described.

Note: The reasoning shortcut for any of these: hair + nails + teeth + sweat glands all derive from ECTODERM, so when the stem lists several of them together, you are in the ectodermal dysplasia family. The added skull finding narrows it to cranioectodermal dysplasia.