[Genetic diffuse cystic lung disease in adults]

Multiple cystic lung diseases comprise a wide range of various diseases, some of them of genetic origin. Lymphangioleiomyomatosis (LAM) is a disease occurring almost exclusively in women, sporadically or in association with tuberous sclerosis complex (TSC). Patients with LAM present with lymphatic complications, renal angiomyolipomas and cystic lung disease responsible for spontaneous pneumothoraces and progressive respiratory insufficiency. TSC and LAM have been ascribed to mutations in TSC1 or TSC2 genes. Patients with TSC are variably affected by cutaneous, cognitive and neuropsychiatric manifestations, epilepsy, cerebral and renal tumors, usually of benign nature. Birt-Hogg-Dubé syndrome is caused by mutations in FLCN encoding folliculin. This syndrome includes lung cysts of basal predominance, cutaneous fibrofolliculomas and various renal tumors. The main complications are spontaneous pneumothoraces and renal tumors requiring systematic screening. The mammalian target of rapamycin (mTOR) pathway is involved in the pathophysiology of TSC, sporadic LAM and Birt-Hogg-Dubé syndrome. MTOR inhibitors are used in LAM and in TSC while Birt-Hogg-Dubé syndrome does not progress towards chronic respiratory failure. Future challenges in these often under-recognized diseases include the need to reduce the delay to diagnosis, and to develop potentially curative treatments. In France, physicians can seek help from the network of reference centers for the diagnosis and management of rare pulmonary diseases.

Lethal form of spinocerebellar ataxia type 7 with early onset in childhood

Progressive cerebellar ataxias are well-known hereditary neurological disorders. Among them, spinocerebellar ataxia type 7 (SCA7) is inherited as an autosomal dominant trait and is ascribed to the expansion of a CAG trinucleotide repeat within the ATXN7 gene. An anticipation phenomenon can occur during paternal transmission and sometimes is responsible for a severe infantile form. The specificity of SCA7 is the retinal involvement with retinitis pigmentosa and cone rod dystrophy. We describe a familial form with two siblings who died of a severe infantile form. Diagnosis was made in their father, who had a recent history of macular atrophy and presented with gait disturbance thereafter. Retrospectively, substantial triplet repeat expansion was confirmed in the two affected infants. These infantile forms are rare and difficult to diagnose in the absence of suggestive family symptoms.

Combined genetic approaches yield a 48% diagnostic rate in a large cohort of French hearing-impaired patients

Hearing loss is the most common sensory disorder and because of its high genetic heterogeneity, implementation of Massively Parallel Sequencing (MPS) in diagnostic laboratories is greatly improving the possibilities of offering optimal care to patients. We present the results of a two-year period of molecular diagnosis that included 207 French families referred for non-syndromic hearing loss. Our multi-step strategy involved (i) DFNB1 locus analysis, (ii) MPS of 74 genes, and (iii) additional approaches including Copy Number Variations, in silico analyses, minigene studies coupled when appropriate with complete gene sequencing, and a specific assay for STRC. This comprehensive screening yielded an overall diagnostic rate of 48%, equally distributed between DFNB1 (24%) and the other genes (24%). Pathogenic genotypes were identified in 19 different genes, with a high prevalence of GJB2, STRC, MYO15A, OTOF, TMC1, MYO7A and USH2A. Involvement of an Usher gene was reported in 16% of the genotyped cohort. Four de novo variants were identified. This study highlights the need to develop several molecular approaches for efficient molecular diagnosis of hearing loss, as this is crucial for genetic counselling, audiological rehabilitation and the detection of syndromic forms.

Genetic variation in TGFB1 gene and risk of idiopathic recurrent pregnancy loss

Transforming growth factor β1 plays a significant role in pregnancy outcome. We investigated the association of TGFB1 exon 1 (rs1800471, rs1800470) and promoter region (rs1800469, rs1800468) polymorphisms with recurrent pregnancy loss (RPL) in 675 Tunisian women: 304 women with a history of three consecutive pregnancy losses of unknown etiology with the same partner and 371 age-matched multiparous control women. TGFB1 genotyping was done by TaqMan assays. Higher minor allele frequency for rs1800471 (P< 0.001), but not for rs1800470, rs1800469 or rs1800468 was found in RPL cases compared with controls. A significant difference in the distribution of rs1800471 genotypes was seen between the RPL cases and control women, irrespective of the genetic model used. Increased RPL risk was seen with rs1800471 allele C in the heterozygous state and to a greater degree in the homozygous state, thus establishing a dose-dependent effect. Haploview analysis revealed differential linkage disequilibrium between the TGFB1 single-nucleotide polymorphisms analyzed. TGFB1 haplotype analysis identified eight common haplotypes (rs1800471/rs1800470/rs1800469/rs1800468) with three (GTTG, Pc = 0.02; CCTG, Pc = 0.02 and CTCG, Pc = 0.02) positively associated with RPL and one (GCCG, Pc = 0.009) negatively associated with RPL. This study provides the first evidence that the TGFB1 genotype may influence RPL.

[Pregnancy and Ehlers-Danlos vascular syndrome: patients' care and complications]

INTRODUCTION

Elhers-Danlos vascular syndrome type IV (EDS4) is a hereditary pathology of the connective tissue responsible for an increased risk of lethal arterial, uterine and digestive complications during and after pregnancy.

PATIENTS AND METHODS

We describe the obstetrical care, the nature and frequency of complications related to pregnancy of patients with EDS4 and their relatives.

RESULTS

Twenty-seven pregnancies were studied including 23 deliveries, 18 vaginal deliveries and five caesarean, no maternal death and two major life-threatening complications (8.7%) were recorded which could be directly linked to EDS4 (rupture of the biscupid valve pillar after vaginal delivery and a rupture of the caecum after a prophylactic caesarean). Ten deliveries underwent epidural anesthesia without complication. Six perineal injuries (33.3%) were observed.

CONCLUSION

Pregnancy in patient with EDS4 needs obstetrical cares in a special unit's motivated medical team with intensive care and surgical disponibilities.

Binder phenotype in mothers affected with autoimmune disorders

OBJECTIVE

To report four foetal cases of the Binder phenotype associated with maternal autoimmune disorders.

PATIENTS AND METHODS

In three mothers with autoimmune diseases, 2D and 3D ultrasonographic measurements were made on four foetuses with the Binder profile, and were compared with postnatal phenotypes.

RESULTS

The Binder phenotype can be detected in early pregnancy (14.5 WG). All foetuses had verticalized nasal bones and midfacial hypoplasia. Punctuate calcifications were found in almost all the cases. No specific maternal auto-antibody has been associated with foetal Binder phenotype.

CONCLUSION

Since the Binder phenotype can be diagnosed at ultrasound examination during pregnancy, it is important to establish the underlying cause so as to assess the foetal prognosis. This study stresses the importance of systematic checks for maternal autoimmune disease in cases of prenatally diagnosed Binder phenotypes.

The Renpenning syndrome spectrum: new clinical insights supported by 13 new PQBP1-mutated males

Since the first reports of polyglutamine-binding protein 1 (PQBP1) mutations in Renpenning syndrome and related disorders, the spectrum of PQBP1-linked clinical manifestations has been outlined from rare published case reports. The phenotypic description is often obtained from medical archives, and therefore, heterogeneous. Moreover, some aspects such as brain imaging or cognitive and behavioral functioning are rarely described. In this study, 13 PQBP1-mutated French patients were subjected to a standardized clinical, cognitive and behavioral assessment. Physical measurements of their relatives were also collected. We report on a recognizable clinical and radiological phenotype. All patients presented with microcephaly, leanness and mild short stature, relative to familial measurements. Three new clinical features are described: upper back progressive muscular atrophy, metacarpophalangeal ankylosis of the thumb and velar dysfunction. The specific facial dysmorphic features included at least four of the following signs: long triangular face, large ridged nose, half-depilated eyebrows, dysplastic or protruding ears and rough slightly sparse hair. An over-aged appearance was noticed in elderly patients. Cortical gyrification was normal based on available magnetic brain imaging of six patients. PQBP1-linked microcephaly (or Renpenning syndrome) is an X-linked mental retardation syndrome, which has clinically recognizable features.

Expanding CEP290 mutational spectrum in ciliopathies

Ciliopathies are an expanding group of rare conditions characterized by multiorgan involvement, that are caused by mutations in genes encoding for proteins of the primary cilium or its apparatus. Among these genes, CEP290 bears an intriguing allelic spectrum, being commonly mutated in Joubert syndrome and related disorders (JSRD), Meckel syndrome (MKS), Senior-Loken syndrome and isolated Leber congenital amaurosis (LCA). Although these conditions are recessively inherited, in a subset of patients only one CEP290 mutation could be detected. To assess whether genomic rearrangements involving the CEP290 gene could represent a possible mutational mechanism in these cases, exon dosage analysis on genomic DNA was performed in two groups of CEP290 heterozygous patients, including five JSRD/MKS cases and four LCA, respectively. In one JSRD patient, we identified a large heterozygous deletion encompassing CEP290 C-terminus that resulted in marked reduction of mRNA expression. No copy number alterations were identified in the remaining probands. The present work expands the CEP290 genotypic spectrum to include multiexon deletions. Although this mechanism does not appear to be frequent, screening for genomic rearrangements should be considered in patients in whom a single CEP290 mutated allele was identified.

Binder phenotype: clinical and etiological heterogeneity of the so-called Binder maxillonasal dysplasia in prenatally diagnosed cases, and review of the literature

OBJECTIVE

Prenatal Binder profile is a well known clinical phenotype, defined by a flat profile without nasal eminence, contrasting with nasal bones of normal length. Binder profile results of a hypoplasia of the nasal pyramid (sometimes referred to as maxillonasal dysplasia). We report 8 fetuses prenatally diagnosed as Binder phenotype, and discuss their postnatal diagnoses.

METHODS

Ultrasonographic detailed measurements in 2D and 3D were done on the 8 fetuses with Binder profile, and were compared with postnatal phenotype.

RESULTS

All fetuses have an association of verticalized nasal bones, abnormal convexity of the maxilla, and some degree of chondrodysplasia punctata. The final diagnoses included fetal warfarin syndrome (one patient), infantile sialic acid storage (one patient), probable Keutel syndrome (one patient), and five unclassifiable types of chondrodysplasia punctata.

CONCLUSION

This series demonstrates the heterogeneity of prenatally diagnosed Binder phenotype, and the presence of chondrodysplasia punctata in all cases. An anomaly of vitamin K metabolism, possibly due to environmental factors, is suspected in these mild chondrodysplasia punctata. We recommend considering early prophylactic vitamin K supplementation in every suspected acquired vitamin K deficiency including incoercible vomiting of the pregnancy.

Epistatic interactions with a common hypomorphic RET allele in syndromic Hirschsprung disease

Hirschsprung disease (HSCR) stands as a model for genetic dissection of complex diseases. In this model, a major gene, RET, is involved in most if not all cases of isolated (i.e., nonsyndromic) HSCR, in conjunction with other autosomal susceptibility loci under a multiplicative model. HSCR susceptibility alleles can harbor either heterozygous coding sequence mutations or, more frequently, a polymorphism within intron 1, leading to a hypomorphic RET allele. On the other hand, about 30% of HSCR are syndromic. Hitherto, the disease causing gene has been identified for eight Mendelian syndromes with HSCR: congenital central hypoventilation (CCHS), Mowat-Wilson (MWS), Bardet-Biedl (BBS), Shah-Waardenburg (WS4), cartilage-hair-hypoplasia (CHH), Smith-Lemli-Opitz (SLO), Goldberg-Sprintzsen (GSS), and hydrocephalus due to congenital stenosis of the aqueduct of sylvius (HSAS). According to the HSCR syndrome, the penetrance of HSCR trait varies from 5 to 70%. Trisomy 21 (T21) also predisposes to HSCR. We were able to collect a series of 393 patients affected by CCHS (n = 173), WS4 (n = 24), BBS (n = 51), MWS (n = 71), T21 (n = 46), and mental retardation (MR) with HSCR (n = 28). For each syndrome, we studied the RET locus in two subgroups of patients; i.e., with or without HSCR. We genotyped the RET locus in 393 patients among whom 195 had HSCR, and compared the distribution of alleles and genotypes within the two groups for each syndrome. RET acts as a modifier gene for the HSCR phenotype in patients with CCHS, BBS, and Down syndrome, but not in patients with MWS and WS4. The frequent, low penetrant, predisposing allele of the RET gene can be regarded as a risk factor for the HSCR phenotype in CCHS, BBS, and Down syndrome, while its role is not significant in MWS and WS4. These data highlight the pivotal role of the RET gene in both isolated and syndromic HSCR.

Acute renal failure in a patient with phosphofructokinase deficiency

A 16-year-old Caucasian girl was admitted to hospital with acute renal failure and hemolytic anemia due to rhabdomyolysis following a 3-km walk. (31)P-magnetic resonance spectroscopy provided characteristic spectra of type VII glycogen storage disease (phosphofructokinase deficiency).

Large-scale deletions and SMADIP1 truncating mutations in syndromic Hirschsprung disease with involvement of midline structures

Hirschsprung disease (HSCR) is a common malformation of neural-crest-derived enteric neurons that is frequently associated with other congenital abnormalities. The SMADIP1 gene recently has been recognized as disease causing in some patients with 2q22 chromosomal rearrangement, resulting in syndromic HSCR with mental retardation, with microcephaly, and with facial dysmorphism. We screened 19 patients with HSCR and mental retardation and eventually identified large-scale SMADIP1 deletions or truncating mutations in 8 of 19 patients. These results allow further delineation of the spectrum of malformations ascribed to SMADIP1 haploinsufficiency, which includes frequent features such as hypospadias and agenesis of the corpus callosum. Thus, SMADIP1, which encodes a transcriptional corepressor of Smad target genes, may play a role not only in the patterning of neural-crest-derived cells and of CNS but also in the development of midline structures in humans.

[Persistent hyperplastic primary vitreous syndrome in a girl with Aicardi syndrome]

Aicardi syndrome is characterized by infantile spasms, agenesis of the corpus callosum and chorioretinal lacunae. This disorder affects mostly females with early embryonic lethality in males. We present a case of persistent hyperplastic primary vitreous (PHPV) in association with Aicardi syndrome in a 2-year-old girl.

Use of a herpes thymidine kinase/neomycin phosphotransferase chimeric gene for metabolic suicide gene transfer

Metabolic suicide gene transfer is widely applied for gene therapy of cancer, and retroviral vectors expressing the herpes simplex virus thymidine kinase (HSV-tk) gene are commonly used in clinical trials. Most of these vectors contain positive selectable markers that undoubtedly facilitate the determination of viral titer and the identification of high-titer producer clones. However, the presence of additional transcriptional units may result in reduced expression of the gene of interest. The use of fusion genes expressing bifunctional proteins may help to overcome this problem. We have constructed a retroviral vector carrying the TNFUS69 chimeric gene, which originates from the fusion of the HSV-tk and neomycin phosphotransferase II genes, and evaluated the functional expression of the encoded fusion protein. In vitro, expression of the fusion gene conferred to target cells both resistance to neomycin and selective sensitivity to the antiherpetic drugs ganciclovir and (E)-5-(2-bromovinyl)-2'-deoxyuridine. Cells transduced with the fusion gene, however, showed reduced ability to phosphorylate ganciclovir compared with cells expressing the native HSV-tk. Therefore, although the fusion gene may be used as a constituent of retroviral cassettes for positive and negative selection in vitro, its usefulness for suicide gene transfer applications in vivo may depend upon the possibility of using (E)-5-(2-bromovinyl)-2'-deoxyuridine in a clinical context.

[Molecular genetics of Hirschsprung disease: a model of multigenic neurocristopathy]

Hirschsprung's disease (HSCR, aganglionic megacolon) is a frequent congenital malformation regarded as a multigenic neurocristopathy. Three susceptibility genes have been recently identified in HSCR, namely the RET proto-oncogene, the endothelin B receptor (EDNRB) gene, and the endothelin 3 (EDN3) gene. RET gene mutations were found in significant proportions of familial (50%) and sporadic (15-20%) HSCR, while homozygosity for EDNRB or EDN3 mutations accounted for the rare HSCR-Waardenburg syndrome (WS) association. More recently, heterozygous EDNRB an EDN3 missense mutations have been reported in isolated HSCR patients. Some of these results were obtained after the identification of mouse genes whose natural or site-directed mutations resulted in megacolon and coat color spotting. There is also conclusive evidence for the involvement of other independent loci in HSCR. In particular, the recent identification of neurotrophic factors acting as RET ligands (GDNF and Neurturin) provide additional candidate genes for HSCR. The dissection of the genetic etiology of HSCR disease may then provide a unique opportunity to distinguish between a polygenic and a genetically heterogeneous disease, thereby helping to understand other complex disorders and congenital malformations hitherto considered as multifactorial in origin. Finally, the study of the molecular bases of HSCR is also a step towards the understanding of developmental genetics of the enteric nervous system giving support to the role of the tyrosine kinase and endothelin-signaling pathways in the development of neural crest-derived enteric neurons in human.

Mutation of the RET ligand, neurturin, supports multigenic inheritance in Hirschsprung disease

Hirschsprung disease (HSCR) is a frequent neurocristopathy characterized by the absence of submucosal and myenteric plexuses in a variable length of the gastrointestinal tract. Pedigrees and segregation analyses suggested the involvement of one or several dominant genes with low penetrance in HSCR. Considering that RET and glial cell line-derived neurotrophic factor (GDNF) mutations have been reported in the disease, we regarded the other RET ligand, neurturin (NTN), as an attractive candidate gene, especially as it shares large homologies with GDNF. Here, we report on the finding of a heterozygous missense NTN mutation in a large non-consanguineous family including four children affected with a severe aganglionosis phenotype extending up to the small intestine. Interestingly, it appears that the NTN mutation reported here is not sufficient to cause HSCR, and this multiplex family also segregates a RET mutation. This cascade of independent and additive genetic events fits well with the multigenic pattern of inheritance expected in HSCR, and further support the role of RET ligands in development of the enteric nervous system.

MR cholangiography in neonates and infants: feasibility and preliminary applications

OBJECTIVE

The objective of the study was to evaluate the accuracy of MR cholangiography in showing the biliary tree in neonates and infants and to show preliminary applications in a pediatric population.

SUBJECTS AND METHODS

MR cholangiography was performed with T2-weighted turbo spin-echo sequences (8000/300 [TR/TE], six or eight excitations). The study included seven patients with suspected bile duct disorders and 10 control individuals.

RESULTS

In the control group, the extrahepatic bile ducts (EHBDs) were revealed by MR cholangiography in all patients. In one of the five patients with neonatal cholestasis, biliary atresia was excluded by identifying the entire EHBD on MR cholangiograms. In the four other patients with neonatal cholestasis, biliary atresia was suspected because the EHBD could not be seen on MR cholangiography. The diagnosis was confirmed in three of these four patients, in whom the MR finding was associated with significant periportal thickening. In the remaining patient, in whom periportal thickening was not seen, sclerosing cholangitis was diagnosed on biopsy. In the sixth patient with neonatal cholestasis, who had received a liver transplant, MR cholangiography showed biliary dilatation above the biliary-digestive anastomosis. In the seventh patient, a neonate with a prenatal diagnosis of hepatic cyst, MR cholangiography showed a choledochal cyst.

CONCLUSION

MR cholangiography may become an important diagnostic tool in the detection of biliary atresia, congenital choledochal dilatation, and biliary complications in hepatic transplantation for pediatric patients.

l-folinic acid versus d,l-folinic acid in rescue of high-dose methotrexate therapy in children

BACKGROUND

At this time, folinic acid (FA) is commercially available as the racemic mixture d,l-FA, whose biological activity is supported by natural l-FA. The administration of d,l-FA results in the accumulation of d-FA in plasma relative to the active l-FA form; in vitro studies have shown that d-FA can compete with the polyglutamation of methotrexate (MTX).

PURPOSE

Our purpose was to compare, on a pharmacokinetic, biological, and clinical basis, the racemic mixture d,l-FA with the pure l-FA in rescue of high-dose MTX therapy (5 g/m2) in children with acute lymphocytic leukemia (ALL).

METHODS

Eighteen children with ALL were entered in this trial, which was planned with a crossover design. Four cycles of MTX were administered to each patient, and rescue was achieved orally every 6 hours at a dose of 12 mg/m2 for d,l-FA and 6 mg/m2 for pure l-FA. The d,l-FA and l-FA rescues were alternated from one cycle to the next. d-FA, l-FA, and the active metabolite 5-methyltetrahydrofolate (5-MTHF) were measured in plasma using a stereospecific high-performance liquid chromatography assay.

RESULTS

Considering total active folate levels (l-FA + 5-MTHF), mean residual concentrations were similar for rescue by d,l-FA and l-FA, after two and six intakes, respectively: 92 and 186 nM for d,l-FA rescue versus 100 and 184 nM for l-FA rescue. Intra-individual comparison of total active folates (l-FA + 5-MTHF) did not show any significant difference between d,l-FA rescue and l-FA rescue. After administration of d,l-FA, the accumulation of d-FA in plasma was confirmed. For both types of FA rescue, MTX terminal half-lives were identical (average value, 13.9 hours). Considering each type of toxic effect (hematologic, hepatic, renal, and digestive), there was no significant difference in the proportion of toxic cycles following l-FA rescue or d,l-FA rescue.

CONCLUSION

The administration of the pure l-FA, compared with the administration of the racemic mixture, results in comparable blood profiles of active folates and MTX, leads to equivalent treatment tolerance, and avoids the plasma accumulation of d-FA.

Sclerodermatous chronic graft-versus-host disease. Analysis of seven cases

BACKGROUND

Sclerodermatous chronic graft-versus-host disease is a disabling complication after allogeneic bone marrow transplantation from HLA-identical sibling donors. Only a few series of patients have been reported and the dermatologic features have never been extensively described.

OBJECTIVE

The purpose of the study was to describe clinical and biologic features of chronic sclerodermatous graft-versus-host disease and to compare them with scleroderma.

METHODS

We reviewed 196 patients grafted between April 1973 and July 1987 with survival times sufficient to be at risk of chronic graft-versus-host disease. Seven had the sclerodermatous form.

RESULTS

Most patients had disseminated sclerosis of the trunk and the proximal portions of the limbs. In two cases, atrophy of the skin was predominant, corresponding with a severe clinical evolution. Periorbital pigmentation was observed as an initial manifestation in three cases. Visceral manifestations resembled those observed in scleroderma but histologic and immunologic studies demonstrated clear differences. Response to therapy was variable.

CONCLUSION

Chronic sclerodermatous graft-versus-host disease may realize two different patterns. Major atrophy is associated with a more severe progression.

Prognostic factors and predictive signs of malignancy in adult dermatomyositis. A study of 32 cases

Dermatomyositis (DM) is an inflammatory myopathy with a severe prognosis mainly determined by its association with malignancy. We present the results of a study of 32 adults with DM. Our aim was to define predictive signs of cancer and establish prognostic factors according to patient survival. Thirteen (41%) of the 32 patients had DM associated with malignancy. After 7 years of follow-up, the overall mortality rate was 52%. Mortality was higher for patients with malignancy. Cutaneous necrosis and an elevated erythrocyte sedimentation rate appeared as potential markers of associated malignancy. Classic signs of poor prognosis, such as age and association with cancer were found. Interestingly, extensive cutaneous lesions on the trunk and an elevated erythrocyte sedimentation rate were also more frequent among the patients who died. Our results demonstrate that selected groups of patients with DM, in part defined by cutaneous signs, have a poor prognosis.

Toxic epidermal necrolysis. Clinical findings and prognosis factors in 87 patients

Eighty-seven patients with toxic epidermal necrolysis were observed at Hôpital Henri Mondor in Créteil, France, over the last 12 years. The mean percentage of body surface area involved was 39%. Erosive mucous membrane lesions, identical to those of Stevens-Johnson syndrome, were present in all but three cases. Necrolysis was sometimes generalized within 24 hours but usually spread progressively after a Stevens-Johnson syndrome-like aspect at the onset. Mortality was 25%. Infection, mainly with Staphylococus aureus and Pseudomonas aeruginosa, was the first cause of death, clearly responsible in ten of 20 cases. Age, extension of necrolysis, idiopathic nature of toxic epidermal necrolysis, ingestion of many drugs, elevation of urea, creatinine, and glucose levels, neutropenia, lymphopenia, and thrombocytopenia were statistically linked to a bad prognosis. A multivariant analysis showed that three of these prognosis factors are of paramount importance, namely: age, area of necrolysis, and serum urea level. Pigmentary changes and sicca syndrome were frequently observed sequelae in survivors.

Genetic susceptibility to toxic epidermal necrolysis

The pathophysiologic events leading to toxic epidermal necrolysis (TEN) remain unknown. With the idea of an immunologically mediated reaction occurring in predisposed subjects we performed HLA-A, -B and -DR typing in 44 patients surviving TEN. We observed a significant increase of only HLA-B12, previously found associated with ocular complications of Stevens-Johnson syndrome. When patients were stratified according to the drugs involved as causes for their TEN, we found other HLA phenotypes associated with B12, varying with each category of drugs. Sulfonamide-related cases of TEN were linked to A29, B12, and DR7, while oxicam-related cases of TEN were linked to A2 and B12. These results suggest that a genetic background, related to the major histocompatibility complex, may contribute to severe blistering drug reactions.

The culprit drugs in 87 cases of toxic epidermal necrolysis (Lyell's syndrome)

Between 1972 and 1985, 87 patients with toxic epidermal necrolysis (TEN) were admitted to the dermatological intensive care unit at Hôpital Henri Mondor, Créteil, France. The culpable drug was determined by standardized criteria. Only three patients had received no drugs before the onset of TEN. Most patients (71 of 87) were receiving more than one drug. Patients had taken an average of 4.4 +/- 3.4 drugs each. A culpable drug was determined in 67 patients (77%). The mean time from first drug administration to onset of TEN was 13.6 +/- 8.4 days. The culprit drugs included the following: sulfonamides, 18 cases, and especially sulfamethoxazole and trimethoprim, 12; anticonvulsants, seven (barbiturates and carbamazepine only); nonsteroidal anti-inflammatory drugs, 29 (especially the phenylbutazone derivative, 16, and oxicam derivatives, 10); allopurinol, three; chlormezanone, three; and others, seven. Aspirin, antipyretics, and antibiotics are infrequently implicated in this series. The pattern of culprit drugs changed with years. The level of sulfonamide-related TEN remained the same, while incidence of nonsteroidal anti-inflammatory drug-induced TEN increased sharply, the introduction of oxicam derivatives being in part responsible.