Summary Carbamazepine (CBZ) has been reported as the most common culprit drug for Stevens‐Johnson syndrome (SJS) and toxic epidermal necrolysis (TEN) in several Asian countries including Thailand. A strong association between HLA‐B*1502 and CBZ‐induced SJS/TEN has been reported in Han Chinese but not in Caucasian and Japanese populations. A case–control study was conducted to determine whether HLA‐B*1502 is a valid pharmacogenetic test for SJS/TEN caused by CBZ in a Thai population. Among 42 CBZ‐induced patients with SJS/TEN, 37 (88.10%) patients carried the HLA‐B*1502 while only 5 (11.90%) of the CBZ‐tolerant controls had this allele. The risk of CBZ‐induced SJS/TEN was significantly higher in the patients with HLA‐B*1502, with an odds ratio (OR) of 54.76 [95% confidence interval (CI) 14.62–205.13, p = 2.89 × 10−12]. The sensitivity and specificity of HLA‐B*1502 for prediction of CBZ‐induced SJS/TEN were 88.10%. By assuming a 0.27% as a prevalence rate of CBZ‐induced SJS/TEN in a Thai population, the positive predictive value (PPV) and negative predictive value (NPV) of the HLA‐B*1502 were 1.92% and 99.96%. Results from this study suggest that HLA‐B*1502 may be a useful pharmacogenetic test for screening Thai individuals who may be at risk for CBZ‐induced SJS and TEN.

Lhermitte-Duclos disease (LDD) is a disorder sometimes referred to as a dysplastic gangliocytoma of the cerebellum. This is a focally indolent growth of the cerebellar cortex in which the folia enlarge due to a profusion of dysplastic cortical neurons and a thickening of the molecular layer. Loss of Purkinje cells and thinning of medullary white matter results. The enlarged folia lose their secondary foldings and asymmetrically expand the cerebellar hemisphere. These morphologic features produce a characteristic pattern on some CTs and all MRIs, affording an opportunity for a preoperative diagnosis. MRI of a pathologic specimen suggested that the abnormal T1 and T2 signals corresponded to the atrophic folial white matter, thickened granule cell layer, and outer molecular layer. Because of inherent Hounsfield artifact in posterior fossa with CT, MRI is the imaging modality of choice, with better visualized striated pattern. The uniqueness of these imaging features obviates the need for an obligatory biopsy for asymptomatic patients and either permits more definitive planning for surgical decompression or, in restricted lesions, guides more assuredly complete excision of the cerebellar mass.

Neither SJS/TEN nor DRESS caused by phenytoin was significantly associated with the HLA-B*15:02. The CYP2C9*3 variant was significantly associated with phenytoin-related SJS/TEN, but not DRESS. Certain alleles of HLA, particularly HLA-B*56:02, were significantly associated with phenytoin-related SCAR in the study population.