Med. J. Malaysia Vol. 45 No. 4 December 1990 Cerebrotendinous xanthomatosis with cholestanolaemia - involvement of five individuals in a Malay family NorHayati Othman, MBBS, M.Path Lecturer Sabariah Abdul Rahman, MBBS, M.Path Lecturer Department of Pathology, School of Medical Sciences, Universiti Sains Malaysia, 16150 Kubang Kerian, Kelantan. Summary Cerebrotendinous xanthomatosis (CTX), a rare inherited lipid storage disease is due to a defect in bile acid metabolism. Involvement of five members of a family is presented. The clinical features, laboratory and pathologic findings are discussed. Tendinous and tuberous x,:nthomatosis, bilateral cataracts, cerebral impairment and raised serum cholestanol are the salient features. We believe this is the first report of CTX in Malaysia. Key words: Cerebrotendinous xanthomatosis, cholestanolaemia, involvement of five individuals in a Malay family. Introduction In 1937 Van Bogeart, Scheren and Epstein described a disease cha'racterised by distinct symptoms such as dementia, ataxia, cataracts and xanthomas. 1 ,2,3 The clinical features of CTX are insidious and unpredictable. The initial stage usually begins in childhood and is characterised ·by mental retardation or a decrease in intellectual functions. Juvenile cataracts are seen during adolescence or early adulthood. Tendon xanthomas have been observed in the second decade but usually are not noticed until the third or fourth decades, the Achilles tendon being the most common site. Death usually results from progressive neurologic deterioration. CTX is an autosomal recessive disorder. The underlying biochemical defect is a deficiency of C27 steroid 26 - hydroxylase,4 an important enzyme in the synthesis of bile acids. s The serum, bile, urine, xanthomatous tissue and cerebrospinal fluid (CSF) of these patients show raised cholestanol levels, with either low or normal serum cholesterollevels. 1 ,3,6 To the best of our knowledge CTX has not been reported in Malaysia. Compared to other cases of CTX reported in the literature world-wide to date, this report records what is possibly the largest number of individuals with CTX in a single family. 1 ,2 Case Report M.A.O, a 36 year old Malay male presented to the Orthopaedic Unit with a complaint of progressive swelling of the right Achilles tendon. The swelling became ulcerated and infected for 275