TY - JOUR T1 - Mutation of the sterol 27-hydroxylase gene (<em>CYP27</em>) results in truncation of mRNA expressed in leucocytes in a Japanese family with cerebrotendinous xanthomatosis JF - Journal of Neurology, Neurosurgery &amp; Psychiatry JO - J Neurol Neurosurg Psychiatry SP - 675 LP - 677 DO - 10.1136/jnnp.67.5.675 VL - 67 IS - 5 AU - K Shiga AU - R Fukuyama AU - S Kimura AU - K Nakajima AU - S Fushiki Y1 - 1999/11/01 UR - http://jnnp.bmj.com/content/67/5/675.abstract N2 - OBJECTIVES A Japanese family with cerebrotendinous xanthomatosis (CTX) was investigated for a sequence alteration in the sterol 27-hydroxylase gene (CYP27). The expression ofCYP27 has been mostly explored using cultured fibroblasts, prompting the examination of the transcripts from blood leucocytes as a simple and rapid technique. METHODS An alteration in CYP27 of the proband was searched for by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis and subsequent sequencing. Samples of RNA were subjected to reverse transcription PCR (RT-PCR) and the product of the proband was amplified with nested primers and sequenced. RESULTS A homozygous G to A transition at the 5′ end of intron 7 was detected in the patient. In RT-PCR analysis, only a truncated transcript was detected in the patient, whereas both normal and truncated transcripts were detected in the siblings. The sequencing of the patient’s cDNA fragment disclosed a direct conjuction of exon 6 and exon 8. CONCLUSION The mutation at splice donor site and the truncation of mRNA were identical with those of a recently reported Italian patient, although different in symptomatology. The application of blood leucocytes can be a simple technique on analysing a constructive abnormality ofCYP27 mRNA. ER -