Summary: Purpose: Previous studies found a strong association between HLA‐B*1502 and carbamazepine (CBZ)‐induced Stevens‐Johnson syndrome (SJS) in Han Chinese, but not in Caucasian populations. Even in Han Chinese, the HLA‐B*1502 was not associated with CBZ‐induced maculopapular eruptions (MPE). This study seeks to identify whether HLA‐B*1502 is associated with CBZ‐ or phenytoin (PHT)‐induced SJS or MPE in a Thai population.Methods: Eighty‐one Thai epileptic patients between 1994 and 2007 from the Chulalongkorn Comprehensive Epilepsy Program were recruited. Thirty‐one subjects had antiepileptic drug (AED)‐induced SJS or MPE (6 CBZ‐SJS, 4 PHT‐SJS, 9 CBZ‐MPE, 12 PHT‐MPE), and 50 were AED‐tolerant controls.Results: For the first time, a strong association between HLA‐B*1502 and PHT‐induced SJS was found (p = 0.005). A strong association was also found between the HLA‐B*1502 and CBZ‐induced SJS (p = 0.0005), making Thai the first non‐Chinese population demonstrating such an association. Some patients, who were HLA‐B*1502 and suffered from CBZ‐induced SJS, could be tolerant to PHT and vice versa. This suggests that HLA‐B*1502 may be a common attribute required for a Thai patient to develop SJS from these two AEDs; other different elements, however, are also needed for each AED. In addition, no association between HLA‐B alleles and CBZ‐ or PHT‐induced MPE was found.Conclusions: CBZ‐ and PHT‐induced SJS, but not MPE, is associated with HLA‐B*1502 allele in Thai population.

Hermansky–Pudlak syndrome is characterized by oculocutaneous albinism, a storage-pool deficiency, and lysosomal accumulation of ceroid lipofuscin, which causes pulmonary fibrosis and granulomatous colitis in some cases. All identified affected patients in northwest Puerto Rico are homozygous for a 16-bp duplication in exon 15 of a recently cloned gene, HPS. We compared the clinical and laboratory characteristics of these patients with those of patients without the 16-bp duplication. Forty-nine patients — 27 Puerto Ricans and 22 patients from the mainland United States who were not of Puerto Rican descent — were given a diagnosis on the basis of albinism and the absence of platelet dense bodies. We used the polymerase chain reaction to determine which patients carried the 16-bp duplication. Twenty-five of the Puerto Rican patients were homozygous for the 16-bp duplication, whereas none of the non–Puerto Rican patients carried this mutation. Like the patients without the duplication, the patients with the 16-bp duplication had a broad variation in pigmentation. Nine of 16 adults with the duplication, but none of the 10 without it, had a diffusing capacity for carbon monoxide that was less than 80 percent of the predicted value. High-resolution computed tomography in 12 patients with the 16-bp duplication revealed minimal fibrosis in 8, moderate fibrosis in 1, severe fibrosis in 1, and no fibrosis in 2. Computed tomography in eight patients without the duplication revealed minimal fibrosis in three and no fibrosis in the rest. Inflammatory bowel disease developed in eight patients (four in each group) between 3 and 25 years of age. The 16-bp duplication in exon 15 of HPS, which we found only in Puerto Rican patients, is associated with a broad range of pigmentation and an increased risk of restrictive lung disease in adults.