Subject(s)
Famous Persons , Periodicals as Topic , Publishing , Humans , Music , Poetry as Topic , PublicationsABSTRACT
BACKGROUND: Most studies on offending heterogeneity have been conducted with general population samples. It is not clear to what extent these can inform such outcomes for individuals with substance use disorders specifically. AIMS: The aim of this study is to compare the offending trajectories of individuals treated for substance use disorders in adolescence with a matched general population sample, and to test for gender differences in this respect. METHOD: Growth mixture models were applied to identify offending trajectories from age 15 to 33 of 1568 individuals treated for substance use disorders in adolescence, and in a matched population-based sample of 1500 individuals. RESULTS: Several parallel trajectories for men and for women were identified in both samples. The substance misuse treatment sample, however, had higher levels of offending, larger offender classes, longer careers and two additional, distinct trajectories. Although there were similarities between the men and women, the men were more heterogeneous offenders. There were two distinct offending trajectories among male substance misusers-decreasing high level and decreasing low level offending. CONCLUSIONS: Differences between substance using and general population samples indicate that results from the latter could underestimate the severity, heterogeneity, and persistence of offending trajectories if merely generalised to individuals with substance use disorders. Our results also indicated that population--based samples might be underpowered for detecting female offending heterogeneity.
Subject(s)
Criminals/psychology , Substance-Related Disorders/psychology , Substance-Related Disorders/therapy , Violence , Adolescent , Adult , Case-Control Studies , Female , Humans , Male , Middle Aged , Sex Distribution , Violence/psychology , Violence/statistics & numerical data , Young AdultABSTRACT
Glutathione (GSH) is present in all mammalian tissues and plays a crucial role in many cellular processes. The second and final step in the synthesis involves the formation of GSH from gamma-glutamylcysteine (γ-GC) and glycine and is catalyzed by glutathione synthetase (GS). GS deficiency is a rare autosomal recessive disorder, and is present in patients with a range of phenotypes, from mild hemolytic anemia and metabolic acidosis to severe neurologic disorders or even death in infancy. The substrate for GS, γ-GC, has been suggested as playing a protective role, by substituting for GSH as an antioxidant in GS deficient patients. To examine the role of GS and GSH metabolites in development, we generated mice deficient in GSH by targeted disruption of the GS gene (Gss). Homozygous mice died before embryonic day (E) 7.5, but heterozygous mice survived with no distinct phenotype. GS protein levels and enzyme activity, as well as GSH metabolites, were investigated in multiple tissues. Protein levels and enzyme activity of GS in heterozygous mice were diminished by 50%, while GSH levels remained intact. γ-GC could not be detected in any investigated tissue. These data demonstrate that GSH is essential for mammalian development, and GSH synthesis via GS is an indispensable pathway for survival.
Subject(s)
Embryonic Development/genetics , Glutathione Synthase/deficiency , Glutathione Synthase/physiology , Glutathione/physiology , Animals , Disease Models, Animal , Glutathione/biosynthesis , Glutathione Synthase/genetics , Mice , Mice, Knockout , Oxidative StressABSTRACT
Most studies on adolescent offending heterogeneity are based on general population samples, and few include individuals with substance misuse or look specifically at substance-related offending. It is also unclear how offender subtypes develop after young adulthood or how offending heterogeneity varies between genders. This study aimed to identify subgroups of offending among adolescents with misuse problems and to examine associations with offending in adulthood. The study included 1,992 females and males that consulted a clinic for adolescents with misuse problems between 1968 and 1971. Latent Class Analyses were conducted to identify subgroups based on violent and nonviolent offending before age 20. Participants were then followed until age 50 and reexamined regarding violent, nonviolent, and substance-related crimes. Associations between subgroups before age 20 and subgroups age 21-50 were examined. Before age 20, three subgroups were identified among the females and six among the males. Males were more specialized in their offending and demonstrated higher levels of offending. Results pointed to both stability and decrease of violent and nonviolent offending, and to the emergence of substance-related offending in adulthood in both genders. The connection between substance-related crimes and general delinquency in adulthood among individuals treated for substance misuse suggests that interventions should also address substance misuse for reducing the overall volume of crime. This study also highlights the importance of including females in research on offending heterogeneity.
Subject(s)
Crime , Substance-Related Disorders/psychology , Substance-Related Disorders/therapy , Violence , Adolescent , Adult , Crime/psychology , Crime/statistics & numerical data , Female , Follow-Up Studies , Humans , Male , Middle Aged , Sex Factors , Violence/psychology , Violence/statistics & numerical data , Young AdultABSTRACT
BACKGROUND: Adolescents who consult for substance misuse problems are at increased risk for multiple adverse outcomes from ages 21 to 50. METHOD: The sample included 180 adolescents who consulted a clinic for substance misuse and 251 of their parents. Adolescents and parents completed diagnostic interviews and independently completed questionnaires reporting on maltreatment of the adolescents. The adolescents completed questionnaires on substance misuse, illegal activities and relationships with others. Information was extracted from the criminal register. Twelve months later, 86% of the adolescents again completed a diagnostic interview, responded to questions about treatments they had received and completed questionnaires as before. In addition, information was extracted from health and social service files. RESULTS: Six problem domains were defined to include externalizing and internalizing disorders, substance misuse, and violent and non-violent self-reported offending. These were generally stable during the 12-month follow-up, but some adolescents did improve, while others developed new problems. Change in the number of problem domains over the 12-month period was predicted by the number of problem domains present at first contact with the clinic and negatively by treatment during the follow-up period. CONCLUSION: Adolescents who consulted for substance misuse presented multiple mental health and psychosocial problems, which had been present for many years. The multiplicity of problems largely determined outcome 12 months later. Effective interventions are needed to target each problem domain. Identification and intervention with young children presenting mental health problems are needed to avoid the accumulation of problems observed in this sample of adolescents.
Subject(s)
Alcoholism/rehabilitation , Mental Disorders/rehabilitation , Referral and Consultation , Substance-Related Disorders/rehabilitation , Adolescent , Alcoholism/epidemiology , Alcoholism/psychology , Child , Child Abuse/psychology , Child Abuse/statistics & numerical data , Cohort Studies , Comorbidity , Crime/psychology , Crime/statistics & numerical data , Crime Victims/psychology , Female , Follow-Up Studies , Humans , Internal-External Control , Male , Mental Disorders/epidemiology , Mental Disorders/psychology , Outcome and Process Assessment, Health Care , Peer Group , Sex Offenses , Social Behavior , Substance Abuse Treatment Centers , Substance-Related Disorders/epidemiology , Substance-Related Disorders/psychology , Violence/psychology , Violence/statistics & numerical data , Young AdultABSTRACT
AIMS: To examine trajectories of resilience over 25 years among individuals who as adolescents received treatment for substance misuse, the clinical sample (CS) and a matched general population sample (GP). DESIGN: Comparison of the CS and GP over 25 years using Swedish national registers of health care and criminality. SETTING: A substance misuse clinic for adolescents in an urban area in Sweden. MEASUREMENTS: Resilience was defined as the absence of substance misuse, hospitalizations for physical illnesses related to substance misuse, hospitalization for mental illness and law-abiding behaviour from ages 21 to 45 years. PARTICIPANTS: The CS included 701 individuals who as adolescents had consulted a clinic for substance misuse. The GP included 731 individuals selected randomly from the Swedish population and matched for age, sex and birthplace. FINDINGS: A total of 52.4% of the GP and 24.4% of the CS achieved resilience in all domains through 25 years. Among the CS, another one-third initially displayed moderate levels of resilience that rose to high levels over time, one-quarter displayed decreasing levels of resilience over time, while 9.3% showed little but improving resilience and 8.8% showed no resilience. Levels of resilience were associated with the severity of substance misuse and delinquency in adolescence. CONCLUSIONS: Individuals who had presented substance misuse problems in adolescence were less likely to achieve resilience over the subsequent 25 years than was a matched general population sample, and among them, four distinct trajectories of resilience were identified. The severity and type of problems presented in adolescence distinguished the four trajectories.
Subject(s)
Outcome Assessment, Health Care , Resilience, Psychological , Substance Abuse Treatment Centers , Substance-Related Disorders/rehabilitation , Adolescent , Adolescent Behavior , Adolescent Health Services , Adult , Age Factors , Anxiety/epidemiology , Child , Crime/statistics & numerical data , Depression/epidemiology , Epidemiologic Methods , Female , Hospitalization/statistics & numerical data , Humans , Male , Middle Aged , Recurrence , Severity of Illness Index , Socioeconomic Factors , Substance-Related Disorders/epidemiology , Substance-Related Disorders/psychology , Sweden/epidemiology , Urban Population , Young AdultABSTRACT
PURPOSE: To describe the retinal findings in 2 young adults with glutathione synthetase (GS) deficiency, an autosomal-recessive inborn error of glutathione (GSH) metabolism. DESIGN: Report of 2 cases. PARTICIPANTS: Binocular study in 2 affected siblings. METHODS: Two sisters with severe GS deficiency underwent a first ophthalmologic examination including full-field electroretinogram (ERGs). The single flash and flicker ERGs and the oscillatory potentials were measured. The clinical examination was repeated after 1 year with the addition of fluorescein angiography, optical coherence tomography (OCT), and electrooculography (EOG). MAIN OUTCOME MEASURES: Angiograms and the retinal OCTs were analyzed, the morphologic findings compared, and the Arden ratio measured. RESULTS: Myopia decreased in both sisters, and visual acuity remained unchanged. Ophthalmoscopy showed bilateral retinal degenerative changes. Binocular cystic macular edema was present in the fovea and perifoveal areas. Cystic changes were located in the inner nuclear layer and outer plexiform layer. The ERGs showed low or no recordable rod-isolated b-waves, mixed rod-cone a- and b-waves, and cone responses. The oscillatory potentials were subnormal or nonrecordable. The EOG values were subnormal except in 1 eye of the older sister that had a normal Arden ratio. CONCLUSIONS: Severe GS deficiency is associated with progressive retinal dystrophy of the rod-cone type, affecting the central retina with advanced macular edema in adulthood. The retinal degenerative changes in GS deficiency may be the result of the increased oxidative stress accumulated generally in the retina and also apparent in the macular area, and an insufficient level of the free radical scavenger GSH. The patients with GS deficiency may represent a model of the retinal response to oxidative stress in humans. FINANCIAL DISCLOSURE(S): The authors have no proprietary or commercial interest in any materials discussed in this paper.
Subject(s)
Glutathione Synthase/deficiency , Metabolism, Inborn Errors/genetics , Photoreceptor Cells, Vertebrate/pathology , Retinal Degeneration/diagnosis , Retinal Degeneration/genetics , Adult , Disease Progression , Electrooculography , Electrophysiology , Electroretinography , Female , Fluorescein Angiography , Glutathione/metabolism , Humans , Macular Edema/diagnosis , Macular Edema/genetics , Macular Edema/physiopathology , Oscillometry , Photic Stimulation , Retinal Degeneration/physiopathology , Siblings , Tomography, Optical Coherence , Vision, BinocularABSTRACT
INTRODUCTION: Little is known about the long-term outcome of substance misuse by teenagers, this is especially true for gender specific consequences. OBJECTIVES: To examine the prevalence of death, physical illnesses related to substance misuse, mental illness, substance misuse, criminality, and poverty in adulthood among two cohorts of individuals who as adolescents had consulted for substance misuse problems, to estimate the effect of sex on adverse outcomes, and to compare cohort effects. METHODS: Individuals who had consulted a substance misuse clinic as adolescents during 1968-1971 and 1980-1984 were followed until 2002. Adverse outcomes were documented using information from Swedish national registers. RESULTS: In the older cohort followed to age 50, only one-in-five escaped all six adverse outcomes, while over half of subjects experienced at least two or more. Sex and the severity of adolescent substance misuse and delinquency were predictors of adverse outcomes. More women than men experienced physical illness and poverty in the older cohort while more men than women were convicted of criminal offences in both cohorts and presented continued substance misuse in the younger cohort. Men in the younger as compared to the older cohort had higher rates of substance misuse and criminal convictions. CONCLUSIONS: Adolescents seeking help for substance misuse problems are at elevated risk for multiple adverse outcomes later in life. Outcomes differ for women and men and by severity of adolescent misuse and delinquency. Few cohort differences in adult outcomes exist.
Subject(s)
Adolescent Behavior/psychology , Substance-Related Disorders/therapy , Adolescent , Adult , Age Factors , Cohort Studies , Comorbidity , Crime/statistics & numerical data , Female , Health Status , Humans , Juvenile Delinquency/statistics & numerical data , Longitudinal Studies , Male , Mental Disorders/epidemiology , Poverty/statistics & numerical data , Prevalence , Severity of Illness Index , Sex Distribution , Substance Abuse Treatment Centers/statistics & numerical data , Substance-Related Disorders/epidemiology , Substance-Related Disorders/psychology , Treatment OutcomeABSTRACT
Glutathione is a tripeptide composed of glutamate, cysteine and glycine. Glutathione is present in millimolar concentrations in most mammalian cells and it is involved in several fundamental biological functions, including free radical scavenging, detoxification of xenobiotics and carcinogens, redox reactions, biosynthesis of DNA, proteins and leukotrienes, as well as neurotransmission/neuromodulation. Glutathione is metabolised via the gamma-glutamyl cycle, which is catalyzed by six enzymes. In man, hereditary deficiencies have been found in five of the six enzymes. Glutathione synthetase deficiency is the most frequently recognized disorder and, in its severe form, it is associated with hemolytic anemia, metabolic acidosis, 5-oxoprolinuria, central nervous system (CNS) damage and recurrent bacterial infections. Gamma-glutamylcysteine synthetase deficiency is also associated with hemolytic anemia, and some patients with this disorder show defects of neuromuscular function and generalized aminoaciduria. Gamma-glutamyl transpeptidase deficiency has been found in patients with CNS involvement and glutathionuria. 5-Oxoprolinase deficiency is associated with 5-oxoprolinuria but without a clear association with other symptoms. Dipeptidase deficiency has been described in one patient. All disorders are very rare and inherited in an autosomal recessive manner. Most of the mutations are leaky so that many patients have residual enzyme activity. Diagnosis is made by measuring the concentration of different metabolites in the gamma-glutamyl cycle, enzyme activity and in glutathione synthetase and gamma-glutamylcysteine synthetase deficiency, also by mutation analysis. Prenatal diagnosis has been preformed in glutathione synthetase deficiency. The prognosis is difficult to predict, as few patients are known, but seems to vary significantly between different patients. The aims of the treatment of glutathione synthesis defects are to avoid hemolytic crises and to increase the defense against reactive oxygen species. No treatment has been recommended for gamma-glutamyl transpeptidase, 5-oxoprolinase and dipeptidase deficiency.
Subject(s)
Amino Acid Metabolism, Inborn Errors/diagnosis , Amino Acid Metabolism, Inborn Errors/therapy , Glutathione/metabolism , Amino Acid Metabolism, Inborn Errors/genetics , Animals , Diagnosis, Differential , Dipeptidases/deficiency , Genetic Testing/methods , Glutathione Synthase/deficiency , Humans , Prognosis , Pyroglutamate Hydrolase/deficiency , gamma-Glutamyltransferase/deficiencyABSTRACT
The SH compound glutathione (GSH) is involved in several fundamental functions in the cell, including protection against reactive oxygen species (ROS). Here, we studied the effect on oxidative DNA damage in cultured skin fibroblasts from patients with hereditary GSH synthetase deficiency. Our hypothesis was that GSH-deficient cells are more prone to DNA damage than control cells. Single cell gel electrophoresis (the comet assay) in combination with the formamidopyrimidine DNA glycosylase enzyme, which recognizes oxidative base modifications, was used on cultured fibroblasts from 11 patients with GSH synthetase deficiency and five control subjects. Contrary to this hypothesis, we found no significant difference in background levels of DNA damage between cells from patients and control subjects. To study the induction of oxidative DNA damage without simultaneous DNA repair, the cells were gamma-irradiated on ice and DNA single-strand breaks measured. The patient and control cells were equally sensitive to induction of single strand breaks by gamma-irradiation. Therefore, factors other than GSH protect DNA from oxidative damage. However, cells with a high background level of oxidative DNA damage were found to be more sensitive to ionizing radiation. This suggests that differences in background levels of oxidative DNA damage may depend on the cells' intrinsic protection against induction of oxidative damage.
Subject(s)
DNA Damage , DNA/chemistry , DNA/metabolism , Glutathione Synthase/deficiency , Glutathione Synthase/genetics , Oxidative Stress , Adolescent , Adult , Cells, Cultured , Child , Child, Preschool , DNA-Formamidopyrimidine Glycosylase/metabolism , Disease Susceptibility , Female , Fibroblasts , Glutathione/metabolism , Glutathione Synthase/metabolism , Humans , Infant , Infant, Newborn , Male , Oxidation-ReductionABSTRACT
Glutathione synthetase (GS) deficiency is a rare autosomal recessive disorder. The clinical phenotype varies widely, and nearly 30 different mutations in the GSS gene have been identified. In the present study, genotype, enzyme activity, metabolite levels and clinical phenotype were evaluated in 41 patients from 33 families. From some of the patients, data on glutathione (GSH) levels and gamma-glutamylcysteine levels in cultured fibroblasts were also available. Twenty-seven different mutations were found: 14 missense, 9 splice, 2 deletions, 1 insertion and 1 nonsense mutation. Twenty-three patients were homozygous and 18 were compound heterozygous. The moderate and severe clinical phenotypes could not be distinguished based on enzyme activity, GSH or gamma-glutamylcysteine levels in cultured fibroblasts. However, in fibroblasts, the residual GS activity was correlated with the GSH level. All mutations causing frameshifts, premature stop codons or aberrant splicing were associated with moderate or severe clinical phenotypes including haemolytic anaemia, 5-oxoprolinuria, and (in several forms) neurodevelopmental signs. The data indicate that additional genetic or environmental factors modify at least the moderate and severe phenotypes and that the clinical classification given to the patients may be influenced by variation in follow-up. The type of mutation involved can, to some extent, predict a mild versus a more severe phenotype.
Subject(s)
Glutathione Synthase/deficiency , Glutathione/metabolism , Cells, Cultured , Dipeptides/metabolism , Female , Fibroblasts/metabolism , Genotype , Humans , Male , Mutation , PhenotypeABSTRACT
Patients with hereditary glutathione synthetase deficiency suffer from haemolytic anaemia, 5-oxoprolinuria, metabolic acidosis, recurrent bacterial infections and various degrees of central nervous system dysfunction. To investigate the molecular basis of the mutations associated with this disease, seven naturally occurring missense mutations [L188P (Leu188-->Pro), D219A, D219G, Y270C, Y270H, R283C and P314L] were expressed using a His-tagged, Escherichia coli-based expression system. Effects of the mutations on kinetic properties, including negative co-operative binding of gamma-glutamyl substrate, were evaluated. The mutation P314L did not have any major effect on these parameters and was classified as a neutral mutation. The remaining mutations decreased V(max) to 2-27% of wild-type activity. Negative co-operativity for gamma-gluABA (L-gamma-glutamyl-L-alpha-aminobutyric acid) was abolished in five mutant recombinant enzymes, whereas for one mutant enzyme, this co-operativity changed from negative to positive. The structural consequences of the mutations were interpreted on the basis of the known structure of the wild-type enzyme.
Subject(s)
Amino Acid Metabolism, Inborn Errors/enzymology , Glutathione Synthase/deficiency , Glutathione Synthase/metabolism , Glutathione Synthase/chemistry , Glutathione Synthase/physiology , Humans , Models, MolecularABSTRACT
The synthesis of the ubiquitous tripeptide glutathione is impaired in patients with glutathione synthetase deficiency. The defect is inherited in an autosomal recessive manner, and the diagnosis is based on clinical, biochemical, and genetic criteria. In seven of our 30 index cases, however, no disease causing mutations could be identified in the coding exons or exon-intron boundaries of the glutathione synthetase gene GSS. These patients had severely decreased glutathione synthetase activities in lysates of cultured fibroblasts, and the levels of the enzyme were undetectable using a polyclonal antibody raised against human glutathione synthetase. RT-PCR mediated sequence analysis revealed previously not reported splice mutations in all patients. Thus, we conclude that in the investigation of patients with glutathione synthetase deficiency, and probably other genetic diseases as well, it might be time saving to initiate mutation analysis with sequencing of mRNA.
Subject(s)
Glutathione Synthase/deficiency , Metabolism, Inborn Errors/diagnosis , Metabolism, Inborn Errors/enzymology , Blotting, Western , DNA/chemistry , DNA/genetics , DNA Mutational Analysis , DNA, Complementary/chemistry , DNA, Complementary/genetics , Exons/genetics , Female , Fibroblasts/enzymology , Glutathione Synthase/genetics , Glutathione Synthase/metabolism , Humans , Male , Metabolism, Inborn Errors/genetics , MutationABSTRACT
Gender-typed behaviors and interests were investigated in 26 girls, aged 2-10 years, affected with congenital adrenal hyperplasia (CAH) and in 26 unaffected girls matched for age. Girls with CAH were more interested in masculine toys and less interested in feminine toys and were more likely to report having male playmates and to wish for masculine careers. Parents of girls with CAH rated their daughters' behaviors as more boylike than did parents of unaffected girls. A relation was found between disease severity and behavior indicating that more severely affected CAH girls were more interested in masculine toys and careers. No parental influence could be demonstrated on play behavior, nor did the comparison of parents' ratings of wished for behavior versus perceived behavior in their daughters indicate an effect of parental expectations. The results are interpreted as supporting a biological contribution to differences in play behavior between girls with and without CAH.
Subject(s)
Adrenal Hyperplasia, Congenital/psychology , Androgens/physiology , Gender Identity , Prenatal Exposure Delayed Effects , Adrenal Hyperplasia, Congenital/diagnosis , Adrenal Hyperplasia, Congenital/physiopathology , Child , Child, Preschool , Female , Humans , Infant , Parent-Child Relations , Personality Assessment , Play and Playthings , Pregnancy , Psychosexual Development/physiologyABSTRACT
Previous studies have shown that girls with congenital adrenal hyperplasia (CAH), a syndrome resulting in overproduction of adrenal androgens from early fetal life, are behaviorally masculinized. We studied play with toys in a structured play situation and correlated the results with disease severity, assessed by CYP21 genotyping, and age at diagnosis. Girls with CAH played more with masculine toys than controls when playing alone. In addition, we could demonstrate a dose-response relationship between disease severity (i.e. degree of fetal androgen exposure) and degree of masculinization of behavior. The presence of a parent did not influence the CAH girls to play in a more masculine fashion. Four CAH girls with late diagnosis are also described. Three of the four girls played exclusively with one of the masculine toys, a constructional toy. Our results support the view that prenatal androgen exposure has a direct organizational effect on the human brain to determine certain aspects of sex-typed behavior.
Subject(s)
Adrenal Hyperplasia, Congenital/physiopathology , Androgens/physiology , Play and Playthings , Prenatal Exposure Delayed Effects , Sex Characteristics , Steroid 21-Hydroxylase/genetics , Behavior , Brain/drug effects , Brain/embryology , Female , Genotype , Humans , PregnancySubject(s)
Infant, Newborn, Diseases/prevention & control , Adrenal Hyperplasia, Congenital/diagnosis , Adrenal Hyperplasia, Congenital/prevention & control , Biotinidase Deficiency/diagnosis , Biotinidase Deficiency/prevention & control , Congenital Hypothyroidism , Cystic Fibrosis/diagnosis , Cystic Fibrosis/prevention & control , Galactosemias/diagnosis , Galactosemias/prevention & control , Glucosephosphate Dehydrogenase Deficiency/diagnosis , Glucosephosphate Dehydrogenase Deficiency/prevention & control , Hemoglobin SC Disease/diagnosis , Homocystinuria/diagnosis , Homocystinuria/prevention & control , Humans , Hypothyroidism/diagnosis , Hypothyroidism/prevention & control , Infant, Newborn , Infant, Newborn, Diseases/diagnosis , Maple Syrup Urine Disease/diagnosis , Maple Syrup Urine Disease/prevention & control , Metabolism, Inborn Errors/diagnosis , Metabolism, Inborn Errors/prevention & control , Neonatal Screening/methods , Obstetrics , Phenylketonurias/diagnosis , Phenylketonurias/prevention & control , Physician's RoleSubject(s)
DNA Mutational Analysis , Genetic Testing , Neonatal Screening , DNA Mutational Analysis/methods , DNA Mutational Analysis/standards , DNA Mutational Analysis/trends , Genetic Testing/methods , Genetic Testing/standards , Genetic Testing/trends , Humans , Infant, Newborn , Neonatal Screening/methods , Neonatal Screening/standards , Neonatal Screening/trends , Sensitivity and SpecificityABSTRACT
Congenital hypothyroidism affects 1/3000-4000 newborns and it has been estimated that 10-20% are familial cases with an autosomal recessive mode of inheritance. Previous studies of mostly individual cases have led to the identification of mutations in a number of genes, indicating that it is a genetically heterogeneous disease, but no major gene has been identified. In the present investigation, a population-based sample of 23 families with autosomal recessive congenital hypothyroidism, but no signs of goitre, were subject to linkage analysis. When markers located close to the thyroglobulin gene on chromosome 8q24 were used in a two-point analysis allowing for heterogeneity, a Z(max) of 4.10 was obtained with the microsatellite marker D8S557, indicating heterogeneity with 43% of the families being linked. A multipoint analysis using the markers D8S557 and D8S1835 gave a Z(max) of 3.51, assuming homogeneity. There was significant evidence of heterogeneity with 44.5% of the families being linked. The results indicate that a gene in 8q24 is a common cause of familial congenital hypothyroidism. Since thyroglobulin is essential for thyroid physiology, the gene encoding this protein is the obvious candidate for mutation analysis in the linked families.