[Simultaneous pancreas-kidney transplantation. First cases in Chile]

We report two insulin dependent diabetic patients with a past history of 21 and 30 years complicated with retinopathy, neuropathy and nephropathy with arterial hypertension and kidney failure. Simultaneous pancreas-kidney transplantation was done 8 and 18 months after starting hemodialysis, performing a double intraperitoneal implant with pancreato-duodeno-vesical anastomosis and contralateral kidney grafting with uretero vesical anastomosis using antireflux techniques. In the second case, a second kidney transplant from the same donor was needed, due to a thrombosis of renal vein. There was one rejection episode in each case but renal or pancreatic function was not impaired. Other observed complications were metabolic acidosis and hyperkalemia due to urine loss of bicarbonate, moderate arterial hypertension and bacterial and fungal infections. There was a graft dysfunction due to the association of vancomycin and cyclosporin. In conclusion, in the two presented patients, simultaneous pancreas-kidney transplantations were successful and they remain free of insulin or dialytic therapy 4 and 9 months after the operation.

[False high levels glycosylated hemoglobin in 2 diabetic patients with persistence of fetal hemoglobin]

Two diabetic patients with unusual high levels of glycosylated hemoglobin measured by ion exchange chromatography are described. Further studies revealed a persistence of fetal hemoglobin in both cases. This condition produces falsely high levels of glycosylated hemoglobin, when ion exchange chromatography is used. These cases may be overtreated with risk of hypoglycemia. Patients with inappropriate levels of glycosylated hemoglobin should be investigated for hemoglobinopathies.

[Evidence of genetic and environmental factors in manual laterality. Study of 120 Mexican families]

Environmental factors as well as different modes of inheritance has been suggested to explain the etiology of left-handedness. In order to improve knowledge of this problem, manual skill (MS) of parents (n = 234), siblings (n = 506) and children (n = 126) of 60 right-handed (RHI) and 60 left-handed (LHI) index cases (IC), born in Mexico City, were studied. Parents and siblings of both IC had similar frequencies of left-handedness. Quite the contrary, 36.7% of children of LHI were left-handed, while 7.3% children of RHI happen to be left-handed (P < 0.00025). No differences were found in the appearance of perinatal environmental factors. These findings are explained in part according to the pressure exerted by parents and/or teachers for dextrality. The impact of this influence modifies the effect of several unknown genes (multifactorial inheritance). The understanding of the above mechanisms in the etiology of MS is relevant not only for academic purposes, but for the educational sphere as well.

Incongruent parenthood in a Mexican mestizo population as determined by HLA typing

The incidence of incongruent parenthood was determined by confronting the declared familial relationship of 98 father-mother-son/daughter trinomials (drawn from the Centro Médico Nacional-IMSS (CMN-IMSS) Kidney Transplant Program) with their HLA-A and B antigens. Fourteen (14.3%) discrepant cases were found: three each with the putative father (3.1%) or with the putative mother (3.1%), two with either father or mother (though impossible to determine precisely with whom) (2.0%), and six with both parents (6.1%). Several possible explanations of these findings were considered, such as out-of-wedlock pregnancies, complex known or unknown, declared or undeclared social circumstances frequently related to the population studied (i.e. imminent kidney transplantation) and technical pitfalls. These data underscore the level of possible "noise" and imprecision in population genetics; genetic-epidemiology and transplantation programs.

[Histocompatibility antigens and acute vascular purpura]

INTRODUCTION

Some kidney diseases are associated to HLA antigens. Nyulassy found an increase in HLA-B35 in patients with Henoch-Schönlein's purpura suffering nephritis (HSP-N). Our study searched for associations of HLA antigens and anaphylactoid purpura nephritis in Mexican mestizo patients.

MATERIAL AND METHODS

HLA-A,B, and C antigens were detected by two-step microcytotoxicity in 22 patients with HSP-N and compared to those of 665 healthy subjects of the same ethnic background.

RESULTS

A significant association was found between HSP-N and HLA-Aw19 single (pc less than 0.05) or in haplotype form (Aw19-B35) (pc less than 0.005). HLA B35 alone was associated to HSP-N but only at non corrected level (pc less than 0.05).

DISCUSSION

The significant association between HLA-Aw19 and Aw19-B35 and HSP-N may indicate a risk factor in Mexican mestizo patients to develop this case.

[Estimation of the probability of heterozygosity in Duchenne-type progressive muscular dystrophy]

The severe Duchenne type of muscular dystrophy is inherited as an X-linked recessive trait. Approximately two thirds of healthy female heterozygous carriers have a high serum creatine kinase (SCK). A suspected carrier with a normal SCK level therefore, presents an important problem in genetic counselling. Based on Bayesian methods, Emery and Hollyway derived a formula which is applicable when the sporadic case is either the son or brother of a consultant and which also includes information on SCK levels in the consultant and in normal daughters and sisters. The present paper describes the results obtained with use of this formula in 27 families with at least a propositus with Duchenne muscular dystrophy.

Variability between and within laboratories in the analysis of structural chromosomal abnormalities

The frequency of structural chromosomal aberrations in two samples (AM and PM of the same day) from each of nine normal subjects, cultured in two different laboratories, was studied by six observers. The results were analyzed in order to determine the relative importance of inter- and intralaboratory factors in the variability of chromosomal abnormalities. In addition to the difference in the frequency of the abnormalities between the subjects studied, there were differences due to observers from different laboratories (P less than 0.01), as well as between laboratories (P less than 0.01). These results could be explained in part by insufficient agreement between observers from different laboratories and by differences in the quality of the method used.

Complex segregation analysis of diabetes mellitus

Complex segregation analysis was applied to a sample of 12,293 nuclear families each with at least 1 diabetic patient. The families were divided into two groups depending on the proband's treatment: insulin-dependent (IDG) and insulin-independent (IIG). Heterogeneity analysis has revealed a highly significant difference in the IIG group when families were divided into different mating types. The higher recurrence risk was found in the group with affected mothers. Also evidence for a major recessive gene was found in the IGG group, while it was not possible to distinguish between the hypothesis for absence of a major locus and absence of polygenic inheritance in the IDG group. Risks to develop the disease were calculated for a few typical situations.

Intestinal lactase deficiency and milk drinking capacity in the adult

The milk drinking capacity of 200 adults was determined experimentally and the results correlated with their milk drinking habits and intestinal lactase activity as judged by a lactose tolerance test. Of the group 65.5% were found to have deficient lactase activity and 5.3% experienced severe gastrointestinal symptoms with 250 ml of milk; 28.2% with 500 ml; 26.0% with 750 ml; 15.3% with 1000 ml and 25.2% tolerated the latter amount without difficulty. Of the normal individuals, 92.7% tolerated 1000 ml without symptoms. Intestinal lactase activity seemed to be important in determining the extremes of milk ingestion: four or more glasses per day or no milk ingestion, but had little effect in the intermediate pattern of milk consumption. It is concluded that intestinal lactase deficiency has clinical relevance and should be considered when nutritional supplementation with milk is contemplated.

A glucose 6-phosphate dehydrogenase Gd (-) Castilla variant characterized by mild deficiency associated with drug-induced hemolytic anemia

Erythrocyte G-6-PD deficiency is an X-chromosome-linked hereditary trait which is common in many ethnic groups. A deficiency of G-6-PD in red cells is often associated with hemolytic anemia. This report defines a new variant designated as Gd (-) Castilla, which is associated with drug-induced hemolysis. The red cell G-6-PD activity of the variant subject is about 20% of normal. The variant enzyme is thermolabile in vitro and it has faster than normal anodal electrophoretic mobility and normal substrate affinity. The hemolytic problem of the subject might be correlated to sensitivity to NADPH inhibition and molecular instability of the variant enzyme.

Thyroid autoimmunity: increased frequency in relatives of insulin-dependent diabetes patients

Thyroid antibodies were found significantly more often in insulin-dependent diabetics than in their spouses or in non-insulin-dependent diabetics. The poor correlation between presence of thyroid autoimmunity and duration of disease and the significantly increased prevalence of thyroid antibodies in first-degree relatives of insulin-dependent probands are interpreted to suggest that thyroid autoimmunity in probands with insulin-dependent diabetes is not secondary to diabetes. Since married couples in which both members had thyroid antibodies were not found more frequently than predicted by chance alone, acquired environmental factors are not the sole determinants of familial thyroid autoimmunity in diabetes; it is likely that inherited predisposition is of major importance. Relatives of probands with thyroid antibodies have significantly higher frequency of these antibodies than do relatives of negative probands. This finding suggests that there are several kinds of insulin-dependent diabetes, one of which may be an "autoimmune" disease.

Brachydactyly type B and symphalangism in different members of a Mexican family

A patient with typical brachydactyly type B is described. By history, 4 generations had some affected members and it was possible to examine a sister and 2 children of the proposita. These individuals in addition to the brachydactyly had symphalangism, an abnormality not previously described in association with brachydactyly type B.

Hypertrophic pyloric stenosis: adult and congenital types occurring in the same family

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