Ann. Hum. Genet., Lo&. (1964), 27, 413

Printed in Great Britain 413

Haptoglobins and transferrins in patients with Down’s syndrome

BY A. C. HUTTON AND G. F. SMITH*

Starch-gel electrophoresis for distinguishing haptoglobin patterns wm first introduced by Smithies in 1955. Family studies have shown that the haptoglobin patterns are characteristic of an individual and are an inherited character (Smithies & Walker, 1955; Galatius-Jensen, 1958; Harris, Robson & Siniscalco, 1959). Haptoglobin gene frequencies and haptoglobin types for the English population have been determined by Allison, Blumberg & ap Rees (1958) and Harris et al. (1959).

Transferrin, the iron-binding globulin which forms part of the fraction in conventional electro- phoresis, was found to be a genetically controlled character (Horsfall6 Smithies, 1958). Nine different kinds of transferrins have been identified ; however, in the English population trans- ferrin C occurs in most people, and other variants are relatively uncommon (Harris et al. 1958).

Since the haptoglobin and transferrin frequencies and patterns have been established for the English population, it was considered valuable to examine both these proteins in a group of English individuals with Down’s syndrome.

MATERIALS AND METHODS

The starch-gel technique used was that described by Smithies (1955) using the discontinuous buffer system of Poulik (1957). Hydrolysed starch was obtained from the Connaught Labora- tories. Sample insertion was made by cutting the gel transversely and applying the sample on slips of Whatman 3 mm. paper. Benzidine was used for staining on one half of the gel for the haptoglobins and Amido Black 1OB on the other half for the transferrins.

Determinations of the haptoglobin and transferrin types were made according to Smithies (1959).

Blood was obtained from 100 patients with Down’s syndrome from Harperbury Hospital. Of these 100 patients, 68 were male and 32 were female. All the patients were adults with the excep- tion of two females.

RESULTS

Haptoglobin types determined for one hundred English mongols can be seen in Table 1, where they are compared with data of the haptoglobin types found in samples taken from the general English population by Allison et al. (1958) and Harris et al. (1959). In the mongol series there was no significant difference between haptoglobin phenotypes for the males and females (see Table 2).

A comparison was made among the three samples of data irrespective of sex to determine whether these could be considered to have come from the same population. First, the data of Harris et al. (1959) were compared with the data of Allison et al. (1958). Next, the data for the mongol sample were separately compared with the sample of Harris et al. (1959) and then with the sample of Allison et al. (1958). No significant difference was found in any of these comparisons.

* Associate Professor of Pediatrics, University of Miami Medical School, Miami, Florida. National Institutes of Health Fellow at the Galton Laboratory, University College London.

414 A. C. HUTTON AND G. F. SMITH Since there was no statistical difference between the samples of Harris et al. (1959) and Allison et al. (1958), these data could be combined and compared with the mongol data. No significant difference was found between the combined data and the mongol data.

Table 1. Incidence of haptoglobin phenotypes in English population samples Haptoglobin types

7

Samples 0'0 1'1 2'1 2'2 Total

Present series : males 3 I1 30 24 68 females 0 7 18 7 32

Present series : total 3 18 48 31 I 0 0

Harris et al. (1959) 0 33 88 58 I79 Allison et al. (1958) 6 22 I21 69 218

Table 2. Chi-square values for a comparison of haptoglobin phenotypes 1.1, 2.1 and 2.2 in English population samples

Samples compared X2 2 D.F. P

Present series, males : Females 2.245 P > 0-25 Harris et al., Allison et al. 5.6169 P > 0-05

Allison et al. 4'41 23 P > 0'10 P > 0.50

Present series : Harris et al. 0.0057 P > 099

Harris et aE. & Allison et al. 1.2861

The exact percentage of the rare haptoglobin type 0-0 has not been established in populations. In most European samples haptoglobin type 0-0 is found to have a frequency less than 1%. Harris et aZ. (1959) tested 179 normal individuals and found no type 0-0 haptoglobins; however, Allison et aZ. (1958) tested 218 individuals and found six with a type 0-0 haptoglobin pattern

Combining the data of Harris et al. (1959) with those of Allison et al. (1958) there were six type 0-0 individuals out of 397. In the mongol sample there were three type 0-0 out of 100 examined. A separate test for the difference between these samples with respect to the type 0-0 individuals showed it was not statistically significant (x2 = 0.998, 1 D.F.).

The 100 mongols all had a transferrin C pattern. This finding is essentially in agreement with findings in the English population Samples.

(2.7 %).

SUMMARY

100 institutionalized patients with Down's syndrome were examined for their haptoglobin and transferrin patterns. The haptoglobin patterns in mongols were found to be essentially the same as those in the normal population samples. All the mongols were found to have a transferrin C pattern and therefore they were considered to be no different from the general English population.

We wish to thank Prof. L. S . Penrose for his suggestions and assistance; and Dr A. Shapiro and M. Ridler of Harperbury Hospital for their co-operation.

Haptoglobins and transferrins in patients with Down’s syndrome 415

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ALLISON, A. C., BLIJMBERQ, B. S. & AP REES (1958). Haptoglobin types in British, Spanish Basque and

GALATIUS-JENSEN, F. (1958). On the genetics of haptoglobins. Acta Genet. (Bade) , 8, 232. HARRIS, H., ROBSON, E. B. & SINISCALCO, M. (1958). /3 globulin variants in man. Nature, Lond., 182, 452. HARRIS, H., ROBSON, E. B. & SINISCALCO, M. (1959). Genetics of plasma protein variants. Ciba Foundation

HORSFALL, W. R. & SMITHIES, 0. (1958). Genetic control of some human p serum globulins. Science, 128,35. POULIK, M. D. (1967). Starch gel electrophoresis in a discontinuous system of buffers. Nature, Lond., 180,

SMITHIES, 0. (1955). Zone electrophoresis of serum in starch gels. Biochem. J . 61, 629. SMITHIES, 0. (1959). Zone electrophoresis in starch gels. Advanc. Protein Chem. 14, 65. SMITHIES, 0. & WALKER, N. F. (1955). Genetic control of some serum proteins in normal humans. Nature,

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