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. 1995 Oct;73(4):316–320. doi: 10.1136/adc.73.4.316

Factors associated with lowered intelligence in homozygous sickle cell disease.

S Knight 1, A Singhal 1, P Thomas 1, G Serjeant 1
PMCID: PMC1511315  PMID: 7492195

Abstract

The intelligence quotient (IQ) of 60 patients with homozygous sickle cell (SS) disease and 60 age and sex matched controls with a normal haemoglobin (AA) genotype aged 15-18 years, followed up in a cohort study from birth, was assessed by the Wechsler intelligence scales for children or for adults. IQ appeared to be normally distributed in both genotypes but mean values in SS disease were 5.6 points (95% confidence interval (CI) 1.0 to 10.2) lower than in AA controls (p = 0.016). The difference occurred in both verbal (5.5 points, p = 0.017) and performance (5.0 points, p = 0.044) subscales of the IQ score and the IQ defect in SS disease was associated with a significantly lower attention factor score (p = 0.005) but not with other factor scores. The genotype difference in IQ was not accounted for by differences in parental occupational level, school absenteeism, or school drop out, or reported activity level. In SS disease, IQ was not related to mean steady state haemoglobin, fetal haemoglobin, or mean cell haemoglobin concentration, or clinical severity as judged by the frequency of painful crises, hospital admission, or sick visits. IQ, at age 15-18 years, correlated with the patients' height at all ages from 1 to 10 years (partial correlations increasing from 0.14 (p = 0.15) at age 1 to 0.27 (p = 0.004) at age 10). Adjusting for height reduced the mean genotype difference in IQ to 5.5 (95% CI 0.6 to 10.3) points at age 1 and to 2.6 points (95% CI to -2.3, 7.5) at age 10. Prepubertal height therefore accounted for much of the genotype difference in IQ. It is speculated that early factors, possible nutritional, contribute to both impaired growth and mental development in sickle cell disease.

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Selected References

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  1. BEALE R. N., BOSTROM J. O., TAYLOR R. F. Improved rapid methods for the determination of iron content and binding capacity of serum. J Clin Pathol. 1962 Mar;15:156–160. doi: 10.1136/jcp.15.2.156. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. BETKE K., MARTI H. R., SCHLICHT I. Estimation of small percentages of foetal haemoglobin. Nature. 1959 Dec 12;184(Suppl 24):1877–1878. doi: 10.1038/1841877a0. [DOI] [PubMed] [Google Scholar]
  3. Badaloo A., Jackson A. A., Jahoor F. Whole body protein turnover and resting metabolic rate in homozygous sickle cell disease. Clin Sci (Lond) 1989 Jul;77(1):93–97. doi: 10.1042/cs0770093. [DOI] [PubMed] [Google Scholar]
  4. Brown R. T., Armstrong F. D., Eckman J. R. Neurocognitive aspects of pediatric sickle cell disease. J Learn Disabil. 1993 Jan;26(1):33–45. doi: 10.1177/002221949302600104. [DOI] [PubMed] [Google Scholar]
  5. CHODORKOFF J., WHITTEN C. F. Intellectual status of children with sickle cell anemia. J Pediatr. 1963 Jul;63:29–35. doi: 10.1016/s0022-3476(63)80299-1. [DOI] [PubMed] [Google Scholar]
  6. Fowler M. G., Johnson M. P., Atkinson S. S. School achievement and absence in children with chronic health conditions. J Pediatr. 1985 Apr;106(4):683–687. doi: 10.1016/s0022-3476(85)80103-7. [DOI] [PubMed] [Google Scholar]
  7. Fowler M. G., Whitt J. K., Lallinger R. R., Nash K. B., Atkinson S. S., Wells R. J., McMillan C. Neuropsychologic and academic functioning of children with sickle cell anemia. J Dev Behav Pediatr. 1988 Aug;9(4):213–220. [PubMed] [Google Scholar]
  8. Herold S., Brozovic M., Gibbs J., Lammertsma A. A., Leenders K. L., Carr D., Fleming J. S., Jones T. Measurement of regional cerebral blood flow, blood volume and oxygen metabolism in patients with sickle cell disease using positron emission tomography. Stroke. 1986 Jul-Aug;17(4):692–698. doi: 10.1161/01.str.17.4.692. [DOI] [PubMed] [Google Scholar]
  9. Heyman M. B., Vichinsky E., Katz R., Gaffield B., Hurst D., Castillo R., Chiu D., Kleman K., Ammann A. J., Thaler M. M. Growth retardation in sickle-cell disease treated by nutritional support. Lancet. 1985 Apr 20;1(8434):903–906. doi: 10.1016/s0140-6736(85)91677-0. [DOI] [PubMed] [Google Scholar]
  10. Hurtig A. L., Koepke D., Park K. B. Relation between severity of chronic illness and adjustment in children and adolescents with sickle cell disease. J Pediatr Psychol. 1989 Mar;14(1):117–132. doi: 10.1093/jpepsy/14.1.117. [DOI] [PubMed] [Google Scholar]
  11. Pavlakis S. G., Bello J., Prohovnik I., Sutton M., Ince C., Mohr J. P., Piomelli S., Hilal S., De Vivo D. C. Brain infarction in sickle cell anemia: magnetic resonance imaging correlates. Ann Neurol. 1988 Feb;23(2):125–130. doi: 10.1002/ana.410230204. [DOI] [PubMed] [Google Scholar]
  12. Preece M. A., Baines M. J. A new family of mathematical models describing the human growth curve. Ann Hum Biol. 1978 Jan;5(1):1–24. doi: 10.1080/03014467800002601. [DOI] [PubMed] [Google Scholar]
  13. Serjeant B. E., Forbes M., Williams L. L., Serjeant G. R. Screening cord bloods for detection of sickle cell disease in Jamaica. Clin Chem. 1974 Jun;20(6):666–669. [PubMed] [Google Scholar]
  14. Serjeant G. R., Grandison Y., Lowrie Y., Mason K., Phillips J., Serjeant B. E., Vaidya S. The development of haematological changes in homozygous sickle cell disease: a cohort study from birth to 6 years. Br J Haematol. 1981 Aug;48(4):533–543. doi: 10.1111/j.1365-2141.1981.tb02750.x. [DOI] [PubMed] [Google Scholar]
  15. Singhal A., Davies P., Sahota A., Thomas P. W., Serjeant G. R. Resting metabolic rate in homozygous sickle cell disease. Am J Clin Nutr. 1993 Jan;57(1):32–34. doi: 10.1093/ajcn/57.1.32. [DOI] [PubMed] [Google Scholar]
  16. Spurr G. B., Reina J. C. Marginal malnutrition in school-aged Colombian boys: body size and energy costs of walking and light load carrying. Hum Nutr Clin Nutr. 1986 Nov;40(6):409–419. [PubMed] [Google Scholar]
  17. Stevens M. C., Hayes R. J., Serjeant G. R. Body shape in young children with homozygous sickle cell disease. Pediatrics. 1983 Apr;71(4):610–614. [PubMed] [Google Scholar]
  18. Swift A. V., Cohen M. J., Hynd G. W., Wisenbaker J. M., McKie K. M., Makari G., McKie V. C. Neuropsychologic impairment in children with sickle cell anemia. Pediatrics. 1989 Dec;84(6):1077–1085. [PubMed] [Google Scholar]
  19. Walker S. P., Grantham-McGregor S. M. Growth and development of West Indian children. Part I: Growth. West Indian Med J. 1989 Dec;38(4):197–204. [PubMed] [Google Scholar]
  20. Wasserman A. L., Wilimas J. A., Fairclough D. L., Mulhern R. K., Wang W. Subtle neuropsychological deficits in children with sickle cell disease. Am J Pediatr Hematol Oncol. 1991 Spring;13(1):14–20. doi: 10.1097/00043426-199121000-00004. [DOI] [PubMed] [Google Scholar]

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