Complete glucokinase deficiency is not a common cause of permanent neonatal diabetes.
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Diabetes Mellitus↗
Biomedical subjects
J P Shield
Publications and source records attributed to J P Shield.
Micro syndrome in Muslim Pakistan children.
OBJECTIVE: To date, Micro syndrome has been reported in only three children from one family. We describe an additional 14 children from 11 families. DESIGN: Retrospective case series. PARTICIPANTS: Fourteen children from 11 families attending one of five British hospitals. MAIN OUTCOME MEASURES: The following features were documented: pre- and postoperative eye findings, electrophysiologic analysis, systemic abnormalities, development, neuroimaging, genealogy, geographic origin of family. RESULTS: We expand and modify the description of ocular and electrophysiologic findings in Micro syndrome. The eye findings of microphakia, microphthalmos, characteristic lens opacity, and atonic pupils were the presenting feature in all infants and were the most reliable diagnostic signs in the immediate postnatal period. Cortical visual impairment, microcephaly, and developmental delay were not always detectable initially; they developed in all children by 6 months of age. Microgenitalia were a useful diagnostic clue in affected males only. Therefore, eye features were more consistently useful in determining diagnosis than dysmorphology or brain imaging. The families of all the children originate from the Muslim population of Northern Pakistan. Inheritance is likely to be autosomal recessive. CONCLUSIONS: Micro syndrome usually presents to the ophthalmologist, who may be able to make the diagnosis on the basis of characteristic eye findings combined with ethnic origin. Initially, the nature and severity of nonophthalmic features are not apparent. Early diagnosis of the underlying condition is important to guide management of the cataracts, glaucoma, and developmental delay. It is helpful for the family and medical staff to be aware of the low level of vision that develops despite optimal ophthalmic intervention. Genetic counseling extending into the wider family is particularly important in view of the high rate of consanguinity.
Adolescent↗
3-Hydroxyisobutyric aciduria: phenotypic heterogeneity within a single family.
3-Hydroxyisobutyric aciduria is a rare biochemical finding associated with a variable clinical phenotype in the literature. We report two siblings excreting abnormal levels of this metabolite from a consanguineous family who manifested distinct phenotypic variation. We speculate as to whether this biochemical anomaly may simply be an incidental finding and suggest that pre-natal counselling on the basis of metabolite identification may be unwarranted.
Child↗
Pancreatic dysfunction in severe obesity.
AIMS: To investigate pancreatic function in children attending an obesity clinic. METHODS: Thirty six children (of which 34 were white) with severe obesity of prepubertal onset (body mass index more than +2 SDS) were reviewed clinically and dysmorphologically, with assessment of pancreatic function. RESULTS: Eight had dysmorphic features and 13 had learning difficulties. Four of 17 prepubertal children had hyperinsulinaemia and seven had hyperproinsulinaemia. All 19 pubertal children had hyperinsulinaemia, 14 had hyperproinsulinaemia, and one had type II diabetes. CONCLUSIONS: Metabolic abnormalities predictive of type II diabetes occur in severely obese white children.
Adolescent↗
Suggestive evidence for association of human chromosome 18q12-q21 and its orthologue on rat and mouse chromosome 18 with several autoimmune diseases.
Some immune system disorders, such as type 1 diabetes, multiple sclerosis (MS), and rheumatoid arthritis (RA), share common features: the presence of autoantibodies and self-reactive T-cells, and a genetic association with the major histocompatibility complex. We have previously published evidence, from 1,708 families, for linkage and association of a haplotype of three markers in the D18S487 region of chromosome 18q21 with type 1 diabetes. Here, the three markers were typed in an independent set of 627 families and, although there was evidence for linkage (maximum logarithm of odds score [MLS] = 1.2; P = 0.02), no association was detected. Further linkage analysis revealed suggestive evidence for linkage of chromosome 18q21 to type 1 diabetes in 882 multiplex families (MLS = 2.2; lambdas = 1.2; P = 0.001), and by meta-analysis the orthologous region (also on chromosome 18) is linked to diabetes in rodents (P = 9 x 10(-4)). By meta-analysis, both human chromosome 18q12-q21 and the rodent orthologous region show positive evidence for linkage to an autoimmune phenotype (P = 0.004 and 2 x 10(-8), respectively, empirical P = 0.01 and 2 x 10(-4), respectively). In the diabetes-linked region of chromosome 18q12-q21, a candidate gene, deleted in colorectal carcinoma (DCC), was tested for association with human autoimmunity in 3,380 families with type 1 diabetes, MS, and RA. A haplotype ("2-10") of two newly characterized microsatellite markers within DCC showed evidence for association with autoimmunity (P = 5 x 10(-6)). Collectively, these data suggest that a locus (or loci) exists on human chromosome 18q12-q21 that influences multiple autoimmune diseases and that this association might be conserved between species.
Animals↗
An imprinted locus associated with transient neonatal diabetes mellitus.
Recently, we reported the localization of a gene for transient neonatal diabetes mellitus (TNDM), a rare form of childhood diabetes, to an approximately 5.4 Mb region of chromosome 6q24. We have also shown that TNDM is associated with both paternal uniparental disomy (UPD) of chromosome 6 and paternal duplications of the critical region. The sequencing of P1-derived artificial chromosome clones from within the region of interest has allowed us to further localize the gene and to investigate the methylation status of the region. The gene is now known to reside in a 300-400 kb region of 6q24 which contains several CpG islands. At one island we have demonstrated differential DNA methylation between patients with paternal UPD of chromosome 6 and normal controls. In addition, two patients with TNDM, in whom neither paternal UPD of chromosome 6 nor duplication of 6q24 have been found, show a DNA methylation pattern identical to that of patients with paternal UPD of chromosome 6. Control individuals show a hemizygous methylation pattern. These results show that TNDM can be associated with a methylation change and identify a novel methylation imprint on chromosome 6 associated with TNDM.
Blotting, Southern↗
Prevalence of abnormal urinary albumin excretion in adolescents and children with insulin dependent diabetes: the MIDAC study. Microalbinuria in Diabetic Adolescents and Children (MIDAC) research group.
OBJECTIVE: To examine the prevalence of microalbuminuria, defined as an albumin to creatinine ratio (UAC) equal to or greater than 2 mg/mmol in at least two of three early morning urine samples, in adolescents and children with insulin dependent diabetes mellitus. DESIGN: Centrally coordinated, cross sectional, multicentre study in paediatric diabetes outpatient clinics in the United Kingdom and Republic of Ireland. METHODS: Blood and urine samples collected between July 1997 and July 1998 were analysed at a central reference laboratory for HbA(1C) using high performance liquid chromatography, and for urinary albumin and creatinine concentrations from which the UAC was derived (mg/mmol). Clinical data were collected locally and coordinated centrally. SUBJECTS: Patients, aged between 10 and 20 years, with insulin dependent diabetes mellitus for more than a year, attending diabetes outpatient clinics. RESULTS: A total of 1007 patients, comprising 69% of the eligible population of 1451, provided three early morning urine samples. Ninety eight (9.7%) had microalbuminuria using the currently accepted screening cut off of UAC >/= 2 mg/mmol in at least two of three early morning urine samples. Significantly more girls than boys and significantly more pubertal and postpubertal patients had abnormal albumin excretion. Microalbuminuria was not associated with raised blood pressure. CONCLUSIONS: A prevalence of 9.7% for abnormal UAC was found in a cohort of 1007 children and adolescents aged 10-20 years. Thus a tenth of this national sample of young people were identified as being at particular risk of microvascular and later macrovascular disease.
Adolescent↗
The relationship of genotype to cognitive outcome in galactosaemia.
AIMS: To evaluate the cognitive outcome of a cohort of children with galactosaemia in relation to genotype. METHODS: The cohort was drawn from children notified to the British Paediatric Surveillance Unit galactosaemia study which ran from 1988 to 1990. Cognitive outcome was assessed using the Wechsler Intelligence Scale for Children or the Wechsler Preschool and Primary Scale of Intelligence. Parents completed a questionnaire detailing educational status, and the attending paediatrician returned a questionnaire regarding age at diagnosis and biochemical outcome over the previous two years. RESULTS: A total of 45 children were genotyped: 30 were homoallelic for the Q188R mutation, the remainder being heteroallelic for Q188R with K285N (n = 4), L195P (n = 4), or other mutations (n = 7). Psychometric evaluation was available in 34 cases: mean full scale IQ was 79, verbal quotient 79, and performance quotient 82. Genotype was not related to galactose-1-phosphate (Gal-1-P) concentrations. However, children homoallelic for the Q188R mutation had significantly lower IQ scores than those who were heteroallelic (73. 6 v 94.8). This difference was independent of social and demographic influences and Gal-1-P concentrations over the previous two years. CONCLUSIONS: In children with galactosaemia, cognitive outcome appears to relate to genotype rather than metabolic control, as reflected by Gal-1-P concentrations. The value of measuring Gal-1-P concentrations routinely once successfully established on a galactosaemia diet is questionable as concentrations do not appear to affect outcome. In the UK population, homozygosity for the Q188R mutation is invariably associated with a poor outcome, and there is evidence that variability in neurocognitive outcome is at least part dependent on allelic heterogeneity.
Child↗
Neonatal diabetes: new insights into aetiology and implications.
Neonatal diabetes mellitus (NDM) is defined as hyperglycaemia occurring in the first few weeks of life. It can be either transient (TNDM) or permanent (PNDM), and until recently, little was known about the condition. A cohort of 30 infants with a history of TNDM has been studied, and findings have suggested that NDM does not have the same aetiology as classical type 1 childhood diabetes. Uniparental isodisomy of chromosome 6 and an unbalanced duplication of paternal chromosome 6 have both been described as a genetic basis for TNDM in over 75% of the cases. In addition, cerebellar hypoplasia and Walcott-Rallison syndrome have been associated with PNDM, suggesting an autosomal recessive inheritance pattern; furthermore, a mutation in the gene insulin promoter factor 1 has been identified as a cause of pancreatic agenesis in PNDM. In the long term, TNDM may reduce beta cell functional capacity and present a predisposition to type 2 diabetes mellitus.
Chromosome Aberrations↗
Transient neonatal diabetes: widening the understanding of the etiopathogenesis of diabetes.
Transient neonatal diabetes (TND) is a rare type of diabetes that presents soon after birth, resolves by 18 months, and predisposes to diabetes later in life. A total of 30 patients were ascertained and investigated for aberrations of chromosome 6. A genotype/phenotype study was also performed. Genotypically, these patients can be classified into 4 etiologic groups. Group 1 had paternal uniparental isodisomy of chromosome 6 (11 cases, including 1 set of identical twins). Group 2 had a duplication involving chromosome band 6q24, which was paternal in origin where tested (4 sporadic cases and 7 familial cases from 2 families). Group 3 consisted of 1 patient with a loss of methylation at a CpG island within the TND critical region (1 sporadic case). Group 4 had no identifiable rearrangement of chromosome 6 (7 sporadic cases). Most patients were growth retarded at birth, presented at a median age of 3 days, and recovered at a median age of 12 weeks. In group 2, 2 relatives of the TND patients who presented with type 2 diabetes and no early history of TND had inherited an identical duplication. An abnormality of chromosome 6 was identified in approximately 70% of sporadic TND cases and in all familial cases. No significant clinical differences were found between the 4 etiological groups. The study has broadened the clinical spectrum of TND to include type 2 diabetes presenting in later life with no neonatal presentation. The findings are consistent with an imprinted gene for diabetes mapping to 6q24, which we predict will have an important function in normal pancreatic development.
Aneuploidy↗
Is disomic homozygosity at the APECED locus the cause of increased autoimmunity in Down's syndrome?
AIMS: To examine the age of onset of insulin dependent diabetes mellitus (IDDM) in children with Down's syndrome compared with non-trisomic individuals, and to assess whether differences might be related to disomic homozygosity at the autoimmune polyglandular disease type 1 (APECED) gene locus. METHODS: Children with Down's syndrome and IDDM were identified through the Down's syndrome association newsletter and from paediatricians. DNA was extracted from mouthbrush preparations provided by the parents and patients using standard techniques. Mapping techniques were then used to identify areas of reduction to homozygosity, including a marker that overlaps the locus for APECED. The frequency of disomic homozygosity for all markers (n = 18) was compared with a control group of 99 patients with Down's syndrome and their parents. The families also answered a questionnaire concerning diabetes and related autoimmune conditions in the family. Details were compared with the British Paediatric Surveillance Group 1988 diabetes study. RESULTS: Children with Down's syndrome and IDDM were diagnosed significantly earlier than the general population (6.7 v 8.0 years) with a far higher proportion diagnosed in the first 2 years of life (22% v 7%). There was no evidence of increased disomic homozygosity in the region of the APECED locus in Down's syndrome patients with IDDM compared with simple Down's syndrome. CONCLUSIONS: The natural history of IDDM in Down's syndrome is different from that of the general population. Although children with Down's syndrome have features similar to cases of APECED, disomic homozygosity in this region does not explain the predilection for autoimmune disease.
Adolescent↗
Localisation of a gene for transient neonatal diabetes mellitus to an 18.72 cR3000 (approximately 5.4 Mb) interval on chromosome 6q.
Transient neonatal diabetes mellitus (TNDM) is a rare condition which presents with intrauterine growth retardation, dehydration, and failure to thrive. The condition spontaneously resolves before 1 year of age but predisposes patients to type 2 diabetes later in life. We have previously shown that, in some cases, TNDM is associated with paternal uniparental disomy (UPD) of chromosome 6 and suggested that an imprinted gene responsible for TNDM lies within a region of chromosome 6q. By analysing three families, two with duplications (family A and patient C) and one with several affected subjects with normal karyotypes (family B), we have further defined the TNDM critical region. In patient A, polymorphic microsatellite repeat analysis identified a duplicated region of chromosome 6, flanked by markers D6S472 and D6S311. This region was identified on the Sanger Centre's chromosome 6 radiation hybrid map (http://www.sanger.ac.uk/HGP/Chr6) and spanned approximately 60 cR3000. Using markers within the region, 418 unique P1 derived artificial chromosomes (PACs) have been isolated and used to localise the distal breakpoints of the two duplications. Linkage analysis of the familial case with a normal karyotype identified a recombination within the critical region. This recombination has been identified on the radiation hybrid map and defines the proximal end of the region of interest. We therefore propose that an imprinted gene for TNDM lies within an 18.72 cR3000 (approximately 5.4 Mb) interval on chromosome 6q24.1-q24.3 between markers D6S1699 and D6S1010.
Chromosome Mapping↗
Neonatal diabetes mellitus and cerebellar hypoplasia/agenesis: report of a new recessive syndrome.
Classical neonatal diabetes mellitus is defined as hyperglycaemia occurring within the first six weeks of life in term infants. Cerebellar agenesis is rare. We report three cases of neonatal diabetes mellitus, cerebellar hypoplasia/agenesis, and dysmorphism occurring within a highly consanguineous family. This constellation of abnormalities has not previously been described. Two of these cases are sisters and the third case is a female first cousin. The pattern of inheritance suggests this is a previously undescribed autosomal recessive disorder. Prenatal diagnosis of the condition in this family was possible by demonstration of the absence of the cerebellum and severe IUGR.
Cerebellum↗
Fine mapping of the diabetes-susceptibility locus, IDDM4, on chromosome 11q13.
Genomewide linkage studies of type 1 diabetes (or insulin-dependent diabetes mellitus [IDDM]) indicate that several unlinked susceptibility loci can explain the clustering of the disease in families. One such locus has been mapped to chromosome 11q13 (IDDM4). In the present report we have analyzed 707 affected sib pairs, obtaining a peak multipoint maximum LOD score (MLS) of 2.7 (lambda(s)=1.09) with linkage (MLS>=0.7) extending over a 15-cM region. The problem is, therefore, to fine map the locus to permit structural analysis of positional candidate genes. In a two-stage approach, we first scanned the 15-cM linked region for increased or decreased transmission, from heterozygous parents to affected siblings in 340 families, of the three most common alleles of each of 12 microsatellite loci. One of the 36 alleles showed decreased transmission (50% expected, 45.1% observed [P=.02, corrected P=.72]) at marker D11S1917. Analysis of an additional 1,702 families provided further support for negative transmission (48%) of D11S1917 allele 3 to affected offspring and positive transmission (55%) to unaffected siblings (test of heterogeneity P=3x10-4, corrected P=. 01]). A second polymorphic marker, H0570polyA, was isolated from a cosmid clone containing D11S1917, and genotyping of 2,042 families revealed strong linkage disequilibrium between the two markers (15 kb apart), with a specific haplotype, D11S1917*03-H0570polyA*02, showing decreased transmission (46.4%) to affected offspring and increased transmission (56.6%) to unaffected siblings (test of heterogeneity P=1.5x10-6, corrected P=4.3x10-4). These results not only provide sufficient justification for analysis of the gene content of the D11S1917 region for positional candidates but also show that, in the mapping of genes for common multifactorial diseases, analysis of both affected and unaffected siblings is of value and that both predisposing and nonpredisposing alleles should be anticipated.
Chromosome Mapping↗
Transmission of haplotypes of microsatellite markers rather than single marker alleles in the mapping of a putative type 1 diabetes susceptibility gene (IDDM6).
Allelic association methods based on increased transmission of marker alleles will have to be employed for the mapping of complex disease susceptibility genes. However, because the extent of association of single marker alleles with disease is a function of the relative frequency of the allele on disease-associated chromosomes versus non disease-predisposing chromosomes, the most associated marker allele in a region will not necessarily be closest to the disease locus. To overcome this problem we describe a haplotype-based approach developed for mapping of the putative type 1 diabetes susceptibility gene IDDM6. Ten microsatellite markers spanning a 550 kb segment of chromosome 18q21 in the putative IDDM6 region were genotyped in 1708 type 1 diabetic Caucasian families from seven countries. The most likely ancestral diabetogenic chromosome was reconstructed in a stepwise fashion by analysing linkage disequilibrium between a previously defined haplotype of three adjacent markers and the next marker along the chromosome. A plot of transmission from heterozygous parents to affected offspring of single marker alleles present on the ancestral chromosome versus the physical distance between them, was compared with a plot of transmission of haplotypes of groups of three adjacent markers. Analysing transmission of haplotypes largely negated apparent decreases in transmission of single marker alleles. Peak support for association of the D18S487 region with IDDM6 is P = 0.0002 (corrected P = 0.01). The results also demonstrate the utility of polymorphic microsatellite markers to trace and delineate extended and presumably ancient haplotypes in the analysis of common disease and in the search for identical-by-descent chromosome regions that carry an aetiological variant.
Child↗
Paternal uniparental disomy of chromosome 6 and transient neonatal diabetes mellitus.
Transient neonatal diabetes mellitus occurs in growth-retarded infants, has an incidence of 1 in 400000 live births and has been associated with both paternal uniparental disomy of chromosome 6 and paternal duplications of 6q. We analysed samples from our cohort of patients with transient neonatal diabetes mellitus for uniparental disomy of chromosome 6 using polymorphic microsatellite repeat analysis. We report here the fifth case of paternal uniparental disomy of chromosome 6 associated with classic transient neonatal diabetes mellitus and estimate that uniparental disomy of chromosome 6 accounts for approximately one fifth of cases of transient neonatal diabetes mellitus.
Chromosomes, Human, Pair 6↗
Advances in childhood onset diabetes.
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Adolescent↗
Social disadvantage, family composition, and diabetes mellitus: prevalence and outcome.
OBJECTIVE: To investigate the relation between social disadvantage and family composition on diabetes prevalence and diabetes care outcome. DESIGN: Retrospective audit in the south west of England of 801 children with diabetes mellitus. MAIN OUTCOME MEASURES: Prevalence of diabetes in relation to the Townsend index. Admissions to hospital with diabetes related problems, glycated haemoglobin, time spent in hospital, outpatient attendance rates. RESULTS: There was no association between social status and diabetes prevalence. Social deprivation increased the likelihood of admission for hypoglycaemia. Children living with a single parent were more likely to be admitted to hospital with a diabetes related problem and stay in hospital longer. Having either a parent with diabetes or a single parent increased the rates of clinic non-attendance. No association was identified between medium term diabetes control and either social disadvantage or single parent status. CONCLUSIONS: Social disadvantage has no effect on diabetes prevalence and little on diabetes outcome in childhood. Family structure and parental diabetes have adverse effects on some aspects of diabetes outcome.
Adolescent↗