King-Denborough Syndrome is a congenital myopathy that may present with malignant hyperthermia.

Gene affected: RYR1, possibly other


Inheritance: autosomal dominant


Clinical features of King-Denborough syndrome:

(1) dysmorphic facies (micrognathia, low-set ears, high-arched palate, hypertelorism, low-slanting palpebral fissures, ptosis)

(2) cryptorchidism in males

(3) clinodactyly

(4) craniosynostosis

(5) bilateral hearing loss

(6) hypotonia and muscle weakness

(7) short stature

(8) malignant hyperthermia (including heat and exercise intolerance with rhabdomyolysis)

(9) kyphoscoliosis

(10) pectus carinatum

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