Adaptive functioning and academic achievement in pediatric survivors of acute lymphoblastic leukemia: Associations with executive functioning, socioeconomic status, and academic support.

OBJECTIVES: This study examines associations of functional outcomes (adaptive functioning and academic achievement) with executive functioning (EF), socioeconomic status (SES), and academic support in pediatric acute lymphoblastic leukemia (ALL) survivors. METHODS: Fifty survivors of B-lineage ALL treated with chemotherapy-only (42% female, 76% NHW, ages 6-19) were evaluated on performance-based EF and academic achievement, and parent-rated EF and adaptive functioning. Area deprivation and child opportunity (i.e., SES) were extracted using census blocks and tracts. Academic support data were extracted from chart review. RESULTS: Compared to population norms, pediatric ALL survivors demonstrated significantly lower overall adaptive skills and performance in word reading and math calculation (all p ≤ .011). Frequencies of impairment were significantly elevated on all adaptive scales and in math calculation compared to the population (all p ≤ .002). Parent-rated EF significantly predicted overall adaptive skills (p < .001), while performance-based EF significantly predicted word reading and math calculation (all p < .05). Adaptive functioning was not associated with neighborhood-specific variables or academic support. However, academic support predicted word reading (p < .001), while area deprivation and academic support predicted performance-based EF (all p ≤ .02). CONCLUSIONS: Screening of functional outcomes, targeted intervention, and neuropsychological monitoring are necessary to support pediatric ALL survivors' neurocognitive and psychosocial development.

Does MAOA increase susceptibility to prenatal stress in young children?

BACKGROUND: We previously demonstrated a gene-by-prenatal-environment interaction whereby the monoamine oxidase A gene (MAOA) modified the impact of prenatal tobacco exposure (PTE) on adolescent disruptive behavior (DB), with the MAOA risk genotype varying by sex. We extend this work by examining whether this mechanism is evident with another common adversity, prenatal stress exposure (PSE), and whether sex differences are present earlier in development in closer proximity to exposure. METHODS: Participants were 281 mothers and their 285 children derived from a prenatal cohort with in-depth prospective measures of PSE and PTE. We assessed DB at age 5 via dimensional developmentally-sensitive measurement. Analyses were stratified by sex based on prior evidence for sex differences. RESULTS: Concurrent stress exposure predicted DB in children (ß=0.310, p=0.001), while main effects of prenatal exposures were seen only in boys. We found a three-way interaction of MAOA×PSE×sex on DB (ß=0.813, p=0.022). Boys with MAOA-H had more DB as a function of PSE, controlling for PTE (ß=0.774, p=0.015), and as a function of PTE, controlling for PSE (ß=0.362, p=0.037). Boys with MAOA-L did not show this susceptibility. MAOA did not interact with PSE (ß=-0.133, p=0.561) nor PTE (ß=-0.144; p=0.505) in predicting DB in girls. Examination of gene-environment correlation (rGE) showed a correlation between paternal MAOA-L and daughters' concurrent stress exposure (r=-0.240, p=0.013). DISCUSSION: Findings underscore complex mechanisms linking genetic susceptibility and early adverse exposures. Replication in larger cohorts followed from the pregnancy through adolescence is suggested to elucidate mechanisms that appear to have varying developmental expression.

Separating Family-Level and Direct Exposure Effects of Smoking During Pregnancy on Offspring Externalizing Symptoms: Bridging the Behavior Genetic and Behavior Teratologic Divide.

Maternal smoking during pregnancy (MSDP) has been robustly associated with externalizing problems and their developmental precursors in offspring in studies using behavioral teratologic designs (Wakschlag et al., Am J Public Health 92(6):966-974, 2002; Espy et al., Dev Psychol 47(1):153-169, 2011). In contrast, the use of behavior genetic approaches has shown that the effects commonly attributed to MSDP can be explained by family-level variables (D'Onofrio et al., Dev Psychopathol 20(01):139-164, 2008). Reconciling these conflicting findings requires integration of these study designs. We utilize longitudinal data on a preschool proband and his/her sibling from the Midwest Infant Development Study-Preschool (MIDS-P) to test for teratologic and family level effects of MSDP. We find considerable variation in prenatal smoking patterns both within and across pregnancies within families, indicating that binary smoking measures are not sufficiently capturing exposure. Structural equation models indicate that both conduct disorder and oppositional defiant disorder symptoms showed unique effects of MSDP over and above family level effects. Blending high quality exposure measurement with a within-family design suggests that it is premature to foreclose the possibility of a teratologic effect of MSDP on externalizing problems. Implications and recommendations for future studies are discussed.

CYP2A6 Longitudinal Effects in Young Smokers.

INTRODUCTION: The present study sought to identify time-dependent within-participant effects of CYP2A6 genotypes on smoking frequency and nicotine dependence in young smokers. METHODS: Predicted nicotine metabolic rate based on CYP2A6 diplotypes (CYP2A6 diplotype predicted rate [CDPR]) was partitioned into Normal, Intermediate, and Slow categories using a metabolism metric. Growth-curve models characterized baseline and longitudinal CDPR effects with data from eight longitudinal assessments during a 6-year period (from approximately age 16-22) in young smokers of European descent (N = 296, 57% female) who had smoked less than 100 cigarettes lifetime at baseline and more than that amount by Year 6. Phenotypes were number of days smoked during the previous 30 days and a youth version of the Nicotine Dependence Syndrome Scale (NDSS). A zero-inflated Poisson growth-curve model was used to account for the preponderance of zero days smoked. RESULTS: At baseline, Intermediate CDPR was a risk factor relative to both Normal and Slow CDPR for smoking frequency and the NDSS. Slow CDPR was associated with the highest probability of smoking discontinuation at baseline. However, due to CDPR time trend differences, by young adulthood these baseline effects had been reordered such that the greatest risks for smoking frequency and the NDSS were associated with Normal CDPR. CONCLUSIONS: Reduced metabolism CYP2A6 genotypes are associated with both risk and protective effects in novice smokers. However, differences in the time-by-CDPR effects result in a reordering of genotype effects such that normal metabolism becomes the risk variant by young adulthood, as has been reliably reported in older smokers.

Preliminary evidence for the interaction of the oxytocin receptor gene (oxtr) and face processing in differentiating prenatal smoking patterns.

Prenatal smoking cessation has been described as an empathic action "for the baby," but this has not been empirically demonstrated. We capitalized on a genetically-characterized extant dataset with outstanding measurement of prenatal smoking patterns and maternal face processing data (as an indicator of empathy) to test this hypothesis, and explore how empathy and smoking patterns may be moderated by a genetic substrate of empathy, the oxytocin receptor gene (OXTR). Participants were 143 Caucasian women from the East Boston family study with repeated prospective reports of smoking level, adjusted based on repeated cotinine bioassays. Salivary DNA and face processing (Diagnostic Analysis of Nonverbal Accuracy-2) were assessed 14 years later at an adolescent follow-up of offspring. Two-thirds of participants reported smoking prior to pregnancy recognition. Of these, 21% quit during pregnancy; 56% reduced smoking, and 22% smoked persistently at the same level. A significant interaction between face processing and OXTR variants previously associated with increased sensitivity to social context, rs53576GG and rs2254298A, was found (ß = -.181; p = .015); greater ability to identify distress in others was associated with lower levels of smoking during pregnancy for rs53576(GG)/rs2254298(A) individuals (p = .013), but not for other genotypes (p = .892). Testing this "empathy hypothesis of prenatal smoking cessation" in larger studies designed to examine this question can elucidate whether interventions to enhance empathy can improve prenatal smoking cessation rates.

UGT1A and UGT2B genetic variation alters nicotine and nitrosamine glucuronidation in european and african american smokers.

BACKGROUND: Identifying sources of variation in the nicotine and nitrosamine metabolic inactivation pathways is important to understanding the relationship between smoking and cancer risk. Numerous UGT1A and UGT2B enzymes are implicated in nicotine and nitrosamine metabolism in vitro; however, little is known about their roles in vivo. METHODS: Within UGT1A1, UGT1A4, UGT1A9, UGT2B7, UGT2B10, and UGT2B17, 47 variants were genotyped, including UGT2B10*2 and UGT2B17*2. The association between variation in these UGTs and glucuronidation activity within European and African American current smokers (n = 128), quantified as urinary ratios of the glucuronide over unconjugated compound for nicotine, cotinine, trans-3'-hydroxycotinine, and 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanol (NNAL), was investigated in regression models assuming a dominant effect of variant alleles. RESULTS: Correcting for multiple testing, three UGT2B10 variants were associated with cotinine glucuronidation, rs2331559 and rs11726322 in European Americans and rs835309 in African Americans (P ≤ 0.0002). Additional variants predominantly in UGT2B10 were nominally associated with nicotine (P = 0.008-0.04) and cotinine (P = <0.001-0.02) glucuronidation in both ethnicities in addition to UGT2B10*2 in European Americans (P = 0.01, P < 0.001). UGT2B17*2 (P = 0.03) in European Americans and UGT2B7 variants (P = 0.02-0.04) in African Americans were nominally associated with 3HC glucuronidation. UGT1A (P = 0.007-0.01), UGT2B10 (P = 0.02), and UGT2B7 (P = 0.02-0.03) variants in African Americans were nominally associated with NNAL glucuronidation. CONCLUSIONS: Findings from this initial in vivo study support a role for multiple UGTs in the glucuronidation of tobacco-related compounds in vivo, in particular UGT2B10 and cotinine glucuronidation. IMPACT: Findings also provide insight into ethnic differences in glucuronidation activity, which could be contributing to ethnic disparities in the risk for smoking-related cancers. Cancer Epidemiol Biomarkers Prev; 24(1); 94-104. ©2014 AACR.

Genetic factors affecting gene transcription and catalytic activity of UDP-glucuronosyltransferases in human liver.

The aim of this study was to discover cis- and trans-acting factors significantly affecting mRNA expression and catalytic activity of human hepatic UDP-glucuronosyltransferases (UGTs). Transcription levels of five major hepatic UGT1A (UGT1A1, UGT1A3, UGT1A4, UGT1A6 and UGT1A9) and five UGT2B (UGT2B4, UGT2B7, UGT2B10, UGT2B15 and UGT2B17) genes were quantified in human liver tissue samples (n = 125) using real-time PCR. Glucuronidation activities of 14 substrates were measured in 47 livers. We genotyped 167 tagSNPs (single-nucleotide polymorphisms) in UGT1A (n = 43) and UGT2B (n = 124), as well as the known functional UGT1A1*28 and UGT2B17 CNV (copy number variation) polymorphisms. Transcription levels of 15 transcription factors (TFs) known to regulate these UGTs were quantified. We found that UGT expression and activity were highly variable among the livers (median and range of coefficient of variations: 135%, 74-217% and 52%, 39-105%, respectively). CAR, PXR and ESR1 were found to be the most important trans-regulators of UGT transcription (median and range of correlation coefficients: 46%, 6-58%; 47%, 9-58%; and 52%, 24-75%, respectively). Hepatic UGT activities were mainly determined by UGT gene transcription levels. Twenty-one polymorphisms were significantly (FDR-adjusted P < 0.05) associated with mRNA expression and/or activities of UGT1A1, UGT1A3 and UGT2B17. We found novel SNPs in the UGT2B17 CNV region accounting for variability in UGT2B17 gene transcription and testosterone glucuronidation rate, in addition to that attributable to the UGT2B17 CNV. Our study discovered novel pharmacogenetic markers and provided detailed insight into the genetic network regulating hepatic UGTs.

A deletion involving CD38 and BST1 results in a fusion transcript in a patient with autism and asthma.

CD38 encodes a ligand in the oxytocin signaling pathway. Some single nucleotide polymorphisms in this gene have been associated with low serum oxytocin levels in autism spectrum disorder (ASD) patients. Oxytocin disruption has been hypothesized to account for features of ASD, including impaired communication and social behavior, based on animal studies. Recent human studies have shown administration of oxytocin improving emotion recognition, promoting social behavior, and improving auditory processing of social stimuli in ASD patients. In addition to its role in oxytocin signaling, CD38 is involved in the regulation of calcium concentration in airway smooth muscle with impairment of CD38 being implicated in airway diseases like asthma. While a number of studies have implicated rare chromosomal deletions and duplications in helping determine genetic risk for autism, there are to our knowledge no reports describing rearrangements involving CD38 or deletions in patients with ASD. Here, we present two sisters diagnosed with autism and with features of regression-previously acquired speech lost in the second year of life. The younger sister, who also had asthma, inherited a maternal deletion of 4p15.32 that results in a BST1-CD38 fusion transcript. Their mother's deletion was mosaic and she was not affected. Although further work is required to assess functional consequences of the fusion transcript, we hypothesize that the proband's deletion may have served as a risk factor for autism that, when combined with other susceptibility variants, resulted in a more severe presentation than her sister.

Association of the CHRNA4 neuronal nicotinic receptor subunit gene with frequency of binge drinking in young adults.

BACKGROUND: Binge drinking is responsible for over half of all alcohol-related deaths and results in significant health and economic costs to individuals and society. Knowledge of genetic aspects of this behavior, particularly as it emerges in young adulthood, could lead to improved treatment and prevention programs. METHODS: We have focused on the association of variation in neuronal nicotinic receptor subunit genes (CHRNs) in a cohort of 702 Hispanic and non-Hispanic White young adults who are part of the Social and Emotional Contexts of Adolescent Smoking Patterns (SECASP) study. Fifty-five single nucleotide polymorphisms (SNPs) covering the variation in 5 CHRNs (CHRNA4, CHRNB2, CHRNA2, CHRNB3A6, and CHRNA5A3B4) were studied. RESULTS: Frequency of binge drinking and other correlated alcohol consumption measures were significantly associated with SNPs in CHRNA4 (p-values ranged from 0.0003 to 0.02), but not with SNPs in other CHRNs. This association was independent of smoking status in our cohort. CONCLUSIONS: Variants in CHRNA4 may contribute to risk of binge drinking in young adults in this cohort. Results will need to be confirmed in independent samples.

Effect of neuronal nicotinic acetylcholine receptor genes (CHRN) on longitudinal cigarettes per day in adolescents and young adults.

INTRODUCTION: Few studies have sought to identify specific genetic markers associated with cigarettes per day (CPD) during adolescence and young adulthood, the period of greatest vulnerability for the development of nicotine dependence. METHODS: We used a longitudinal design to investigate the effect of neuronal nicotinic acetylcholine receptor (CHRN) subunit genes on CPD from 15 to 21 years of age in young smokers of European descent (N = 439, 59% female). The number of CPD typically smoked during the previous 30 days was self-reported. Single nucleotide polymorphisms (SNPs) from CHRN genes were genotyped using DNA extracted from saliva samples collected at the 5-year assessment. Mixed-model analyses of SNP effects were computed across age at the time of assessment using log-transformed CPD as the phenotype. Data from the 1000 Genomes Project were used to clarify the architecture of CHRN genes to inform SNP selection and interpretation of results. RESULTS: CPD was associated with a CHRNB3A6 region tagged by rs2304297, with CHRNA5A3B4 haplotype C (tagged by rs569207), and with the CHRNA2 SNP rs2271920, ps < .004. The reliability of single-SNP associations was supported by the correspondence between a more extensive set of SNP signals and the underlying genetic architecture. The 3 signals identified in this study appear to make independent contributions to CPD, and their combined effect accounts for 5.5% of the variance in log-transformed CPD. CONCLUSIONS: Level of CPD during adolescence and young adulthood is associated with CHRNB3A6, CHRNA5A3B4, and CHRNA2.

Do dopamine gene variants and prenatal smoking interactively predict youth externalizing behavior?

Externalizing behaviors (encompassing antisocial, impulsive, and substance use behaviors) are pervasive and impairing across a multitude of settings and developmental contexts. These behaviors, though often investigated separately, are highly comorbid. Prenatal tobacco exposure in interaction with various genetic influences has predicted later externalizing behavior, and recent evidence supports investigating sex differences in these patterns. In the current study, we extend this work by (a) examining two functional genetic markers in the dopamine system: the transporter gene (DAT1) and the dopamine receptor D4 gene (DRD4) in interaction with prenatal tobacco exposure to predict a latent composite of externalizing behavior and (b) testing whether these patterns differ by sex of youth in a community sample of adolescents (n=176). The relatively small sample is partially offset by high quality, multi-method prospective measurement. We assessed prenatal tobacco exposure using prospective repeated cotinine-corrected reports and externalizing behaviors were assessed utilizing multiple measures across three waves. The interaction between DAT1 (but not DRD4) and prenatal tobacco exposure was statistically significant in boys, and patterns appeared to differ by sex. Risk for externalizing behaviors for exposed boys increased linearly as a function of the 10r DAT1 allele. For exposed girls, there was a trend such that DAT1 heterozygotes had a marginally higher risk than homozygotes. This pattern was not explained by passive gene-environment correlation. Elucidating sex-specific pathways through which early adverse exposures and genetic susceptibilities contribute to externalizing behavior can inform early targeted prevention efforts for those children at highest risk.

Differences between the pattern of developmental abnormalities in autism associated with duplications 15q11.2-q13 and idiopathic autism.

The purposes of this study were to identify differences in patterns of developmental abnormalities between the brains of individuals with autism of unknown etiology and those of individuals with duplications of chromosome 15q11.2-q13 (dup[15]) and autism and to identify alterations that may contribute to seizures and sudden death in the latter. Brains of 9 subjects with dup(15), 10 with idiopathic autism, and 7 controls were examined. In the dup(15) cohort, 7 subjects (78%) had autism, 7 (78%) had seizures, and 6 (67%) had experienced sudden unexplained death. Subjects with dup(15) autism were microcephalic, with mean brain weights 300 g less (1,177 g) than those of subjects with idiopathic autism (1,477 g; p<0.001). Heterotopias in the alveus, CA4, and dentate gyrus and dysplasia in the dentate gyrus were detected in 89% of dup(15) autism cases but in only 10% of idiopathic autism cases (p < 0.001). By contrast, cerebral cortex dysplasia was detected in 50% of subjects with idiopathic autism and in no dup(15) autism cases (p<0.04). The different spectrum and higher prevalence of developmental neuropathologic findings in the dup(15) cohort than in cases with idiopathic autism may contribute to the high risk of early onset of seizures and sudden death.

Association and mutation analyses of 16p11.2 autism candidate genes.

BACKGROUND: Autism is a complex childhood neurodevelopmental disorder with a strong genetic basis. Microdeletion or duplication of a approximately 500-700-kb genomic rearrangement on 16p11.2 that contains 24 genes represents the second most frequent chromosomal disorder associated with autism. The role of common and rare 16p11.2 sequence variants in autism etiology is unknown. METHODOLOGY/PRINCIPAL FINDINGS: To identify common 16p11.2 variants with a potential role in autism, we performed association studies using existing data generated from three microarray platforms: Affymetrix 5.0 (777 families), Illumina 550 K (943 families), and Affymetrix 500 K (60 families). No common variants were identified that were significantly associated with autism. To look for rare variants, we performed resequencing of coding and promoter regions for eight candidate genes selected based on their known expression patterns and functions. In total, we identified 26 novel variants in autism: 13 exonic (nine non-synonymous, three synonymous, and one untranslated region) and 13 promoter variants. We found a significant association between autism and a coding variant in the seizure-related gene SEZ6L2 (12/1106 autism vs. 3/1161 controls; p = 0.018). Sez6l2 expression in mouse embryos was restricted to the spinal cord and brain. SEZ6L2 expression in human fetal brain was highest in post-mitotic cortical layers, hippocampus, amygdala, and thalamus. Association analysis of SEZ6L2 in an independent sample set failed to replicate our initial findings. CONCLUSIONS/SIGNIFICANCE: We have identified sequence variation in at least one candidate gene in 16p11.2 that may represent a novel genetic risk factor for autism. However, further studies are required to substantiate these preliminary findings.

Population-specific GSTM1 copy number variation.

As one of the major glutathione conjugation enzymes, GSTM1 detoxifies a number of drugs and xenobiotics. Its expression and activity have been shown to correlate both with cancer risks and drug resistance. Through a genome-wide association study, we identified a significant association between HapMap SNP rs366631 and GSTM1 expression. In this study, utilizing lymphoblastoid cell lines derived from International HapMap Consortium CEU and YRI populations, we designed and performed site-specific genotyping assays for both rs366631 and a highly homologous GSTM1 upstream site. Copy number variation (CNV) assays were performed for three different regions of the GSTM1 gene. We demonstrated that HapMap SNP rs366631 is a non-polymorphic site. The false genotyping call arises from sequence homology, a common GSTM1 region deletion and a non-specific genotyping platform used to identify the SNP. However, the HapMap call for rs366631 genotype is an indicator of GSTM1 upstream region deletion. Furthermore, this upstream deletion can be used as a marker of GSTM1 gene deletion. Using a novel GSTM1 CNV assay, we showed a population-specific CNV in this region upstream of the gene. More than 75% of the Caucasian (CEU) samples exhibit GSTM1 deletion and none contain two copies of GSTM1. In contrast, up to 25% of African (YRI) samples were found to have two copies of GSTM1. In conclusion, HapMap rs366631 is a pseudo-SNP that can be used as a GSTM1 deletion marker. Both the pseudo-SNP allele frequency and GSTM1 upstream region CNV show population-specific patterns between CEU and YRI samples.

The Werner's syndrome 4330T>C (Cys1367Arg) gene variant does not affect the in vitro cytotoxicity of topoisomerase inhibitors and platinum compounds.

PURPOSE: Werner's syndrome (WS) is a recessive disorder of premature onset of processes associated with aging. Defective DNA repair has been reported after exposure of cells isolated from WS patients to DNA-damaging agents. The germline 4330T>C (Cys1367Arg) variant in the WS gene (WRN) has been associated with protection from age-related diseases, suggesting it has a functional role. We studied whether the 4330T>C variant confers altered drug sensitivity in vitro. METHODS: 4330T>C was genotyped in 372 human lymphoblastoid cell lines (LCLs) from unrelated healthy Caucasian individuals using a TaqMan-based method. The study was powered to detect the effect of the 4330T>C genotypes after exposure to camptothecin (based upon preliminary data). The effect of the 4330T>C variant on the cytotoxicity of etoposide, carboplatin, cisplatin and daunorubicin was also tested. WRN expression in 57 LCLs was measured by microarray. RESULTS: No significant difference between the IC50 of the cells was observed among genotypes (P = 0.46) after exposure to camptothecin. No association was also observed for etoposide, carboplatin, cisplatin, and daunorubicin (ANOVA, P > 0.05). WRN expression also did not vary across genotypes (ANOVA, P = 0.37). CONCLUSION: These results suggest that this nonsynonymous variant has relatively normal function at the cellular level.

Pharmacogenetics of minimal residual disease response in children with B-precursor acute lymphoblastic leukemia: a report from the Children's Oncology Group.

Minimal residual disease (MRD) as a marker of antileukemic drug efficacy is being used to assess risk status and, in some cases, to adjust the intensity of therapy. Within known prognostic categories, the determinants of MRD are not known. We measured MRD by flow cytometry at day 8 (in blood) and at day 28 (in bone marrow) of induction therapy in more than 1000 children enrolled in Pediatric Oncology Group therapy protocols 9904, 9905, and 9906. We classified patients as "best risk" if they had cleared MRD by day 8 of therapy and as "worst risk" if they had MRD remaining in bone marrow at day 28, and tested whether MRD was related to polymorphisms in 16 loci in genes hypothesized to influence response to therapy in acute lymphoblastic leukemia (ALL). After adjusting for known prognostic features such as presence of the TEL-AML1 rearrangement, National Cancer Institute (NCI) risk status, ploidy, and race, the G allele of a common polymorphism in chemokine receptor 5 (CCR5) was associated with more favorable MRD status than the A allele (P = .009, logistic regression), when comparing "best" and "worst" risk groups. These data are consistent with growing evidence that both acquired and host genetics influence response to cancer therapy.

Relationship of EGFR mutations, expression, amplification, and polymorphisms to epidermal growth factor receptor inhibitors in the NCI60 cell lines.

PURPOSE: The mechanism of sensitivity and resistance to epidermal growth factor receptor (EGFR) inhibitors is incompletely understood, particularly in cancers other than non-small-cell lung cancer (NSCLC). To understand the variable response to this class of drugs, we used the NCI60 cancer cell lines. We aimed to determine if there are interactions between EGFR expression, mutations, polymorphisms, and gene amplification, and whether these factors are associated with variability in response to EGFR inhibitors. EXPERIMENTAL DESIGN: The EGFRVIII and tyrosine kinase (TK) domain mutations were examined in the NCI60 cancer cell lines. Five polymorphisms, -216G/T, -191C/A, intron 1 (CA)n, R497K, and 2607A/G, were genotyped. EGFR amplification was also assessed with high-density single-nucleotide polymorphism chip and real-time PCR, respectively. The results were correlated with cytotoxicity data for erlotinib and other 11 EGFR inhibitors, as well as other publicly available data for these lines. RESULTS: All 12 inhibitors behaved similarly. No EGFRVIII but putative TK mutations in two cell lines were found. Both mutant cell lines were insensitive to all inhibitors. Meanwhile, response did not correlate with EGFR amplification but with EGFR gene expression, especially in the cell lines with relatively normal gene status. In addition, EGFR expression was associated with the -216G/T polymorphism but not with the intron 1 (CA)n polymorphism. A combination of -216G/T and R497K polymorphisms was weakly associated with drug response. CONCLUSIONS: These observations suggest that in addition to TK mutations, germ-line variability may also contribute to the pharmacodynamics of EGFR inhibitors, particularly when EGFR is genetically normal.

Evidence for a susceptibility locus on chromosome 10p15 in early-onset obsessive-compulsive disorder.

BACKGROUND: The goal of this study was to identify chromosomal regions likely to contain susceptibility loci for obsessive-compulsive disorder (OCD). METHODS: We conducted a genome-wide linkage scan, with average marker spacing less than 10 centimorgans (cM), in 121 subjects from 26 families ascertained through probands with early-onset OCD. Best estimate lifetime psychiatric diagnoses were based on semistructured interviews and all other available sources of information. Parametric and nonparametric linkage analyses were conducted with GENEHUNTER+ and Allegro. Family-based association analyses were done using 35 single nucleotide polymorphisms (SNPs) in the 10p15 region. RESULTS: The maximum nonparametric log of odds (NLOD) score was 2.43 on chromosome 10p15 at position 4.37. When data from our first genome scan were added to data from this scan, the maximum NLOD score in the 10p15 region was 1.79. Association was detected on 10p15 with three adjacent SNPs, including the amino acid variant rs2271275 in the 3' region of adenosine deaminase acting on RNA 3 (ADAR3) (p < .05). CONCLUSIONS: The results provide suggestive evidence for linkage on chromosome 10p15. Evidence for association in the linkage region was found with three markers in the 3' end of ADAR3. Limitations include the lack of significant linkage and association findings when corrected for multiple testing.

Ancestry and pharmacogenetics of antileukemic drug toxicity.

Treatment-related toxicity in acute lymphoblastic leukemia (ALL) can not only be life threatening but may also affect relapse risk. In 240 patients, we determined whether toxicities were related to 16 polymorphisms in genes linked to the pharmacodynamics of ALL chemotherapy, adjusting for age, race (self-reported or via ancestry-informative markers), sex, and disease risk group (lower- vs higher-risk therapy). Toxicities (gastrointestinal, infectious, hepatic, and neurologic) were assessed in each treatment phase. During the induction phase, when drugs subject to the steroid/cytochrome P4503A pathway predominated, genotypes in that pathway were important: vitamin D receptor (odds ratio [OR], 6.85 [95% confidence interval [CI], 1.73-27.0]) and cytochrome P4503A5 (OR, 4.61 [95% CI, 1.11-19.2]) polymorphisms were related to gastrointestinal toxicity and infection, respectively. During the consolidation phase, when antifolates predominated, the reduced folate carrier polymorphism predicted gastrointestinal toxicity (OR, 10.4 [95% CI, 1.35-80.4]) as it also did during continuation (OR, 2.01 [95% CI, 1.06-4.11]). In all 3 treatment phases, a glucuronosyltransferase polymorphism predicted hyperbilirubinemia (P = .017, P < .001, and P < .001) and methotrexate clearance (P = .028), which was also independently associated with hyperbilirubinemia (P = .026). The genotype-phenotype associations were similar whether analyses were adjusted by self-reported race or ancestry-informative genetic markers. Germ-line polymorphisms are significant determinants of toxicity of antileukemic therapy.

Association between the casein kinase 1 epsilon gene region and subjective response to D-amphetamine.

Animal models suggest that the casein kinase 1 epsilon gene (Csnk1e) contributes to variability in stimulant response. Csnk1e is a key component in the Darpp-32 (Dopamine-And-cAMP-Regulated-Phosphoprotein-32 kDa) second messenger pathway and has been implicated in previous pharmacological and pharmacogenetic studies in mice. Mice bred for methamphetamine sensitivity showed linkage to the region of chromosome 15 that contains Csnk1e and also showed a 10-fold increase in expression of Csnk1e. We used a double-blind, crossover design in healthy human volunteers to test association between polymorphisms in the CSNK1E region and subjective response to placebo, 10, or 20 mg of oral D-amphetamine. Repeated-measures ANOVA was used to analyze interactions between genotype and drug response. The primary outcome measure, subjects' ratings of whether they felt a drug effect (Drug Effects Questionnaire (DEQ)), revealed a significant effect (p=0.010) at one single-nucleotide polymorphism (rs135745). Subjects with more copies of the rs135745 C allele were more sensitive to the low dose of D-amphetamine (p=0.001), which corresponded to a leftward shift in the dose-response curve. These findings demonstrate the successful translation of pharmacogenetic results from mice to humans.