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. 1994 Apr;31(4):300–305. doi: 10.1136/jmg.31.4.300

Intelligence quotient profile in myotonic dystrophy, intergenerational deficit, and correlation with CTG amplification.

P Turnpenny 1, C Clark 1, K Kelly 1
PMCID: PMC1049802  PMID: 8071955

Abstract

An abbreviated Wechsler Adult Intelligence Scale Revised (WAIS-R) was used to assess verbal and arithmetical cognitive performance in 55 subjects with myotonic dystrophy (DM), covering all grades of disease severity, and 31 controls at 50% risk of inheriting DM. Scaled scores from the assessment were converted into an intelligence quotient (IQ) estimation on each person. Significant IQ differences were found between: (1) all 55 DM subjects (mean 90.2, SD 16.1) and 31 controls (102.6, SD 9.4), with no sex differences in either group; (2) 15 affected parents (99.3, SD 12.2) and their affected children (88.1, SD 17.2), where significance was dependent on parental sex being female; and (3) 15 pairs of affected sibs (89.6, SD 13.2) and their normal sibs (100.2, SD 7.6). IQ steadily declined as (1) the age of onset of signs and symptoms decreased, and (2) the CTG expansion size increased. The correlation appeared to be more linear with age of onset. The correlation of IQ difference and CTG expansion difference in both the DM parent-child pairs and normal sib-affected sib pairs was poor, indicating that CTG expansion is not a reliable predictor of IQ either in individual persons or families. Further analysis of cognitive function in DM is required to clarify specific deficits characteristic of this patient group.

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Selected References

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  1. Aslanidis C., Jansen G., Amemiya C., Shutler G., Mahadevan M., Tsilfidis C., Chen C., Alleman J., Wormskamp N. G., Vooijs M. Cloning of the essential myotonic dystrophy region and mapping of the putative defect. Nature. 1992 Feb 6;355(6360):548–551. doi: 10.1038/355548a0. [DOI] [PubMed] [Google Scholar]
  2. Beijersbergen R. S., Kemp A., van Leeuwen W. S. EEG observations in dystrophia myotonica (Curschmann-Steinert). Electroencephalogr Clin Neurophysiol. 1980 Jul;49(1-2):143–151. doi: 10.1016/0013-4694(80)90360-0. [DOI] [PubMed] [Google Scholar]
  3. Bird T. D., Follett C., Griep E. Cognitive and personality function in myotonic muscular dystrophy. J Neurol Neurosurg Psychiatry. 1983 Nov;46(11):971–980. doi: 10.1136/jnnp.46.11.971. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Brook J. D., McCurrach M. E., Harley H. G., Buckler A. J., Church D., Aburatani H., Hunter K., Stanton V. P., Thirion J. P., Hudson T. Molecular basis of myotonic dystrophy: expansion of a trinucleotide (CTG) repeat at the 3' end of a transcript encoding a protein kinase family member. Cell. 1992 Feb 21;68(4):799–808. doi: 10.1016/0092-8674(92)90154-5. [DOI] [PubMed] [Google Scholar]
  5. Broughton R., Stuss D., Kates M., Roberts J., Dunham W. Neuropsychological deficits and sleep in myotonic dystrophy. Can J Neurol Sci. 1990 Nov;17(4):410–415. doi: 10.1017/s0317167100030985. [DOI] [PubMed] [Google Scholar]
  6. Brumback R. A. Disturbed personality and psychosocial adjustment in myotonic dystrophy: relationship to intellectual/cognitive function and underlying affective disorder (depression). Psychol Rep. 1987 Jun;60(3 Pt 1):783–796. doi: 10.2466/pr0.1987.60.3.783. [DOI] [PubMed] [Google Scholar]
  7. Buxton J., Shelbourne P., Davies J., Jones C., Van Tongeren T., Aslanidis C., de Jong P., Jansen G., Anvret M., Riley B. Detection of an unstable fragment of DNA specific to individuals with myotonic dystrophy. Nature. 1992 Feb 6;355(6360):547–548. doi: 10.1038/355547a0. [DOI] [PubMed] [Google Scholar]
  8. Censori B., Danni M., Del Pesce M., Provinciali L. Neuropsychological profile in myotonic dystrophy. J Neurol. 1990 Jul;237(4):251–256. doi: 10.1007/BF00314629. [DOI] [PubMed] [Google Scholar]
  9. Colombo G., Perini G. I., Miotti M. V., Armani M., Angelini C. Cognitive and psychiatric evaluation of 40 patients with myotonic dystrophy. Ital J Neurol Sci. 1992 Feb;13(1):53–58. doi: 10.1007/BF02222889. [DOI] [PubMed] [Google Scholar]
  10. Crawford J. R., Allan K. M., Jack A. M. Short-forms of the UK WAIS-R: regression equations and their predictive validity in a general population sample. Br J Clin Psychol. 1992 May;31(Pt 2):191–202. doi: 10.1111/j.2044-8260.1992.tb00983.x. [DOI] [PubMed] [Google Scholar]
  11. FRIEDLANDER W. J., BITTENBENDER J. B. EEG FINDINGS IN MYOTONIA DYSTROPHICA. Electroencephalogr Clin Neurophysiol. 1964 Nov;17:564–566. doi: 10.1016/0013-4694(64)90188-9. [DOI] [PubMed] [Google Scholar]
  12. Fiorelli M., Duboc D., Mazoyer B. M., Blin J., Eymard B., Fardeau M., Samson Y. Decreased cerebral glucose utilization in myotonic dystrophy. Neurology. 1992 Jan;42(1):91–94. doi: 10.1212/wnl.42.1.91. [DOI] [PubMed] [Google Scholar]
  13. Glantz R. H., Wright R. B., Huckman M. S., Garron D. C., Siegel I. M. Central nervous system magnetic resonance imaging findings in myotonic dystrophy. Arch Neurol. 1988 Jan;45(1):36–37. doi: 10.1001/archneur.1988.00520250042017. [DOI] [PubMed] [Google Scholar]
  14. Harley H. G., Brook J. D., Rundle S. A., Crow S., Reardon W., Buckler A. J., Harper P. S., Housman D. E., Shaw D. J. Expansion of an unstable DNA region and phenotypic variation in myotonic dystrophy. Nature. 1992 Feb 6;355(6360):545–546. doi: 10.1038/355545a0. [DOI] [PubMed] [Google Scholar]
  15. Harley H. G., Rundle S. A., MacMillan J. C., Myring J., Brook J. D., Crow S., Reardon W., Fenton I., Shaw D. J., Harper P. S. Size of the unstable CTG repeat sequence in relation to phenotype and parental transmission in myotonic dystrophy. Am J Hum Genet. 1993 Jun;52(6):1164–1174. [PMC free article] [PubMed] [Google Scholar]
  16. Harley H. G., Rundle S. A., Reardon W., Myring J., Crow S., Brook J. D., Harper P. S., Shaw D. J. Unstable DNA sequence in myotonic dystrophy. Lancet. 1992 May 9;339(8802):1125–1128. doi: 10.1016/0140-6736(92)90729-m. [DOI] [PubMed] [Google Scholar]
  17. Huber S. J., Kissel J. T., Shuttleworth E. C., Chakeres D. W., Clapp L. E., Brogan M. A. Magnetic resonance imaging and clinical correlates of intellectual impairment in myotonic dystrophy. Arch Neurol. 1989 May;46(5):536–540. doi: 10.1001/archneur.1989.00520410070026. [DOI] [PubMed] [Google Scholar]
  18. Hunter A., Tsilfidis C., Mettler G., Jacob P., Mahadevan M., Surh L., Korneluk R. The correlation of age of onset with CTG trinucleotide repeat amplification in myotonic dystrophy. J Med Genet. 1992 Nov;29(11):774–779. doi: 10.1136/jmg.29.11.774. [DOI] [PMC free article] [PubMed] [Google Scholar]
  19. Koch M. C., Grimm T., Harley H. G., Harper P. S. Genetic risks for children of women with myotonic dystrophy. Am J Hum Genet. 1991 Jun;48(6):1084–1091. [PMC free article] [PubMed] [Google Scholar]
  20. Lavedan C., Hofmann-Radvanyi H., Shelbourne P., Rabes J. P., Duros C., Savoy D., Dehaupas I., Luce S., Johnson K., Junien C. Myotonic dystrophy: size- and sex-dependent dynamics of CTG meiotic instability, and somatic mosaicism. Am J Hum Genet. 1993 May;52(5):875–883. [PMC free article] [PubMed] [Google Scholar]
  21. Lundervold A., Refsum S., Jacobsen W. The EEG in dystrophia myotonica. Eur Neurol. 1969;2(5):279–284. doi: 10.1159/000113804. [DOI] [PubMed] [Google Scholar]
  22. Moxley R. T., Corbett A. J., Minaker K. L., Rowe J. W. Whole body insulin resistance in myotonic dystrophy. Ann Neurol. 1984 Feb;15(2):157–162. doi: 10.1002/ana.410150208. [DOI] [PubMed] [Google Scholar]
  23. Portwood M. M., Wicks J. J., Lieberman J. S., Fowler W. M., Jr Psychometric evaluation in myotonic muscular dystrophy. Arch Phys Med Rehabil. 1984 Sep;65(9):533–536. [PubMed] [Google Scholar]
  24. Ragazzoni A., Pinto F., Taiuti R., Silveri M. C. Myotonic dystrophy: an electrophysiological study of cognitive deficits. Can J Neurol Sci. 1991 Aug;18(3):300–306. doi: 10.1017/s0317167100031851. [DOI] [PubMed] [Google Scholar]
  25. Sinforiani E., Sandrini G., Martelli A., Mauri M., Uggetti C., Bono G., Nappi G. Cognitive and neuroradiological findings in myotonic dystrophy. Funct Neurol. 1991 Oct-Dec;6(4):377–384. [PubMed] [Google Scholar]
  26. Tsilfidis C., MacKenzie A. E., Mettler G., Barceló J., Korneluk R. G. Correlation between CTG trinucleotide repeat length and frequency of severe congenital myotonic dystrophy. Nat Genet. 1992 Jun;1(3):192–195. doi: 10.1038/ng0692-192. [DOI] [PubMed] [Google Scholar]
  27. Woodward J. B., 3rd, Heaton R. K., Simon D. B., Ringel S. P. Neuropsychological findings in myotonic dystrophy. J Clin Neuropsychol. 1982 Dec;4(4):335–342. doi: 10.1080/01688638208401141. [DOI] [PubMed] [Google Scholar]

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