The Genetics of Diabetes Mellitus — A Review of Twin Studies

Langenbeck, U.; Jörgensen, G

doi:10.1007/978-3-642-66332-1_3

Cited by 5 publications

(4 citation statements)

References 31 publications

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“…Barnett et al [5,17] observed a similar tendency in their longitudinal study. Thus, our results are not inconsistent with the other twin and family studies [1][2][3][4][5][6][7][8].…”

Section: Discussionsupporting

confidence: 72%

“…Twin studies have suggested the importance of genetic factors in diabetes mellitus [1][2][3][4]. A genetic influence has been inferred from the greater concordance for disease among monozygotic (identical) twin pairs than among dizygotic (fraternal) twin pairs and from the high concordance among monozygotic twins, particularly as concordance does not occur until later in life when twins no longer share the same environment.…”

mentioning

confidence: 99%

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Concordance for Type 2 (non-insulin-dependent) diabetes mellitus in male twins

et al. 1987

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Concordance for Type 2 (non-insulin-dependent) diabetes was determined in 250 monozygotic and 264 dizygotic white male twin pairs who participated in the National Heart, Lung, and Blood Institute Twin Study. These twins were born between 1917 and 1927 and were identified from military records without regard to disease status. We examined surviving members of the cohort twice--at mean ages of 47 and 57 years--and obtained 1-h post-load glucose tests and medication histories. Diagnostic criteria for Type 2 diabetes included a glucose value greater than or equal to 13.9 mmol/l or current use of antidiabetic medication; possible Type 1 (insulin-dependent) diabetic twins were excluded. A strong genetic predisposition to Type 2 diabetes was suggested by 3 lines of evidence from the second examination: (1) 58% of monozygotic co-twins of diabetic twins were themselves diabetic compared with an expected prevalence of 10%; (2) only 1 of 15 originally disease-discordant, monozygotic twin pairs remained discordant for diabetes; and (3) 65% of non-diabetic monozygotic co-twins of diabetic twins had elevated glucose values. Because concordance for diabetes was less than 100% for twins aged 52-65 years and because twins varied in age at onset of disease, non-genetic factors may also influence diabetes development. Among the 19 monozygotic twins pairs discordant for diabetes, diabetic twins did not differ from their non-diabetic co-twins in obesity, diet, alcohol consumption, or education. However, compared with unrelated non-diabetic twins of the same ages, non-diabetic co-twins of diabetic twins gained more weight as adults (p less than 0.02) and had higher glucose levels (p less than 0.03).

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“…Barnett et al [5,17] observed a similar tendency in their longitudinal study. Thus, our results are not inconsistent with the other twin and family studies [1][2][3][4][5][6][7][8].…”

Section: Discussionsupporting

confidence: 72%

mentioning

confidence: 99%

Concordance for Type 2 (non-insulin-dependent) diabetes mellitus in male twins

et al. 1987

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“…The evidence that IDD is not entirely genetic in its origin comes from studies of identical twins. [11,12,13,14,15]. Our series of identical twins studied at King's College Hospital now comprises 185 pairs (Table 1).…”

Section: Insulin Dependent Diabetes Is Not Entirely Due To Genetic Camentioning

confidence: 99%

Diabetes: The genetic connections

Pyke

1979

Diabetologia

140

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Insulin dependent (IDD) and non-insulin dependent diabetes (NIDD) are separate disorders. Twin studies show that IDD cannot be entirely due to genetic causes as concordance is no more than about 50%, but there is some inherited predisposition to it as shown by HLA patterns. NIDD, on the other hand, is predominantly due to genetic causes since identical twins are nearly always concordant. Many cases of NIDD show chlorpropamide alcohol flushing (CPAF), a dominantly inherited feature which may precede the appearance of diabetes and thus act as a genetic marker for this type of diabetes. Diabetics who show chlorpropamide acohol flushing are less likely to develop retinopathy than those who do not. Genetic factors must therefore affect the incidence and severity of diabetic retinopathy. Chlorpropamide alcohol flushing is due to sensitivity to enkephalin. Enkephalin and other opioids affect carbohydrate metabolism and insulin release. It is possible therefore that they act as neurotransmitters and cause NIDD by a sympathetically mediated effect on the liver and pancreas--in other words, that as far as NIDD is concerned Claude Bernard's views on the cause of diabetes may have been right.

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“…5) When pairs of siblings, where both are diabetic, are tabulated by the interval between onsets there is an excess of both onsets within a one year interval, in comparison with calculated expectancy. 6) Among monozygotic twins where one has diabetes, the second twin is unaffected in about half the instances (104,105) and careful studies suggest that unaffected twins are normal, not prediabetic. This is consistent with the hypothesis that an exogenous event, such as a viral infection, is required to initiate disease.…”

Section: Insulin-dependent Diabetes (Idd)mentioning

confidence: 99%