A 3.9-centimorgan-resolution human single-nucleotide polymorphism linkage map and screening set

Recent advances in technologies for high-throughout single-nucleotide polymorphism (SNP)-based genotyping have improved efficiency and cost so that it is now becoming reasonable to consider the use of SNPs for genomewide linkage analysis. However, a suitable screening set of SNPs and a corresponding linkage map have yet to be described. The SNP maps described here fill this void and provide a resource for fast genome scanning for disease genes. We have evaluated 6,297 SNPs in a diversity panel composed of European Americans, African Americans, and Asians. The markers were assessed for assay robustness, suitable allele frequencies, and informativeness of multi-SNP clusters. Individuals from 56 Centre d'Etude du Polymorphisme Humain pedigrees, with >770 potentially informative meioses altogether, were genotyped with a subset of 2,988 SNPs, for map construction. Extensive genotyping-error analysis was performed, and the resulting SNP linkage map has an average map resolution of 3.9 cM, with map positions containing either a single SNP or several tightly linked SNPs. The order of markers on this map compares favorably with several other linkage and physical maps. We compared map distances between the SNP linkage map and the interpolated SNP linkage map constructed by the deCode Genetics group. We also evaluated cM/Mb distance ratios in females and males, along each chromosome, showing broadly defined regions of increased and decreased rates of recombination. Evaluations indicate that this SNP screening set is more informative than the Marshfield Clinic's commonly used microsatellite-based screening set.

Systematic evaluation of map quality: human chromosome 22

Marker positions on nine genetic linkage, radiation hybrid, and integrated maps of human chromosome 22 were compared with their corresponding positions in the completed DNA sequence. The proportion of markers whose map position is <250 kb from their respective sequence positions ranges from 100% to 35%. Several discordant markers were identified, as well as four regions that show common inconsistencies across multiple maps. These shared discordant regions surround duplicated DNA segments and may indicate mapping or assembly errors due to sequence homology. Recombination-rate distributions along the chromosome were also evaluated, with male and female meioses showing significantly different patterns of recombination, including an 8-Mb male recombination desert. The distributions of radiation-induced chromosome breakage for the GB4 and the G3 radiation hybrid panels were also evaluated. Both panels show fluctuations in breakage intensity, with different regions of significantly elevated rates of breakage. These results provide support for the common assumption that radiation-induced breaks are generally randomly distributed. The present studies detail the limitations of these important map resources and should prove useful for clarifying potential problems in the human maps and sequence assemblies, as well as for mapping and sequencing projects in and across other species.

Adolescence-limited versus persistent delinquency: extending Moffitt's hypothesis into adulthood

The authors examined how neuropsychological, personality, and environmental risk factors and their interactions were related to trajectories of delinquent behavior from adolescence to adulthood. Four waves of longitudinal data from 698 male participants, ages 12-18 at Time 1 and ages 25-31 at Time 4, were included in the analyses. Using a growth mixture model approach, 4 trajectories were identified: nondelinquents, adolescence-limited delinquents, adolescence-to-adulthood-persistent delinquents, and escalating delinquents. Five risk factors distinguished escalating from persistent delinquents and 5 also distinguished nondelinquents from the 3 delinquency trajectories. Persistent delinquents scored significantly higher than adolescence-limited delinquents on only one risk factor, disinhibition. Overall, few of the factors that are related to childhood-to-adolescence persistence were associated with persistence in delinquency beyond adolescence.

Adolescence-limited versus persistent delinquency: extending Moffitt's hypothesis into adulthood

The authors examined how neuropsychological, personality, and environmental risk factors and their interactions were related to trajectories of delinquent behavior from adolescence to adulthood. Four waves of longitudinal data from 698 male participants, ages 12-18 at Time 1 and ages 25-31 at Time 4, were included in the analyses. Using a growth mixture model approach, 4 trajectories were identified: nondelinquents, adolescence-limited delinquents, adolescence-to-adulthood-persistent delinquents, and escalating delinquents. Five risk factors distinguished escalating from persistent delinquents and 5 also distinguished nondelinquents from the 3 delinquency trajectories. Persistent delinquents scored significantly higher than adolescence-limited delinquents on only one risk factor, disinhibition. Overall, few of the factors that are related to childhood-to-adolescence persistence were associated with persistence in delinquency beyond adolescence.

Parental modeling and parenting behavior effects on offspring alcohol and cigarette use. A growth curve analysis

PURPOSE

This paper examined the effects of parental drinking and smoking, parental warmth and hostility, and their interactions on offsprings' drinking and smoking over time.

METHODS

We used four waves of prospective longitudinal data collected from 218 males and 214 females who were age 15 at Time 1 and age 28 by Time 4. Growth mixture modeling was used to develop offspring trajectory groups of cigarette smokers and alcohol drinkers. Logistic regression analyses were conducted to determine whether parent behaviors could predict offspring heavy drinking and smoking trajectories.

RESULTS

Four drinking and three smoking trajectory groups were identified for females and males. Parent drinking rather than parenting behavior predicted heavy drinking by offsprings and mothers' drinking was a slightly better predictor than fathers' drinking for both daughters and sons. Fathers' warmth and hostility was the best predictor of heavy smoking by sons. Neither modeling nor parenting significantly predicted female heavy smoking. For the most part, parent modeling did not interact with parenting behavior to predict smoking or drinking in offspring.

IMPLICATIONS

Parents affected their offspring's use of alcohol and cigarettes both through modeling and parenting behavior. However, the importance of modeling relative to parenting behavior differed by the type of substance. Prevention programs that focus on both the modeling of parental behaviors, as well as enhancing parenting skills, should be effective in influencing trajectories of substance use throughout adolescence and young adulthood.

Clinical and pathologic correlates of stillbirths in a single institution

BACKGROUND

To evaluate risk factors, placental and pathologic determinants of stillbirths.

METHODS

A retrospective analysis of stillbirths > or = 25 weeks was performed. Clinical data was compared to a randomized control group. Statistical analysis included chi square test, student t test, and logistic regression.

RESULTS

One hundred and fifteen stillbirths and 193 controls were analyzed. Maternal age, nulliparity, tobacco use, previous induced abortions, anticardiolipid antibodies, elevated maternal serum alpha feto protein, twins, and amniocentesis, were significantly associated with stillbirth. Logistic regression analysis showed only maternal age, tobacco use, small for gestational age (SGA), previous induced abortions, decreasing gestational age as independent significant variables. The stillbirth baby was 6.8 times more likely to be SGA and 11.9 times more likely to be preterm. Primary pathologic diagnoses were placental factors (37%), cord complications (28%), and fetal causes (15%), 17% had maternal risk factors only and 3% had no known risk factors. Diagnosis was suggested by pathology in 40% of cases.

CONCLUSIONS

Stillbirth delivery is associated with older, nulliparous patients with prenatal complications resulting in intrauterine growth retardation and prematurity. Perinatal histopathologic examination is important in diagnosis. Utilizing an extensive testing protocol will reduce the diagnosis of unexplained stillbirth.