1. Mitochondrial DNA polymorphism in Japanese

   • Satoshi Horai
   • Ei Matsunaga

   Original Investigations Pages: 105 - 117

2. Trisomy 21 Down syndrome

   • Irene A. Uchida
   • C. P. Freeman

   Original Investigations Pages: 118 - 122

3. Segregation analysis of rare autosomal fragile sites

   • S. L. Sherman
   • G. R. Sutherland

   Original Investigations Pages: 123 - 128

4. Detection of bromodeoxyuridine-incorporation in mammalian chromosomes by a bromodeoxyuridine-antibody

   • W. Vogel
   • Margot Autenrieth
   • G. Speit

   Original Investigations Pages: 129 - 132

5. Changes in the incidence of Down syndrome in Sweden during 1968–1982

   • L. Iselius
   • J. Lindsten

   Original Investigations Pages: 133 - 139

6. Unusual supernumerary chromosomes: types encountered in a referred population, and high incidence of associated maternal chromosome abnormalities

   • Judith Stamberg
   • G. H. Thomas

   Original Investigations Pages: 140 - 144

7. Heterogeneity of haplotypes among patients with severe Cooley disease in Eastern Sicily

   • M. Lombardo
   • Angela Ragusa
   • Dominique Labie

   Original Investigations Pages: 145 - 147

8. Synapsis and synaptic adjustment in an infertile human male heterozygous for a pericentric inversion in chromosome 1

   • O. Gabriel-Robez
   • C. Ratomponirina
   • M. R. Guichaoua

   Original Investigations Pages: 148 - 152

9. Assignment of the human tissue-type plasminogen activator gene (PLAT) to chromosome 8

   • J. H. Verheijen
   • R. Visse
   • P. Meera Khan

   Original Investigations Pages: 153 - 156

10. A case of female hemophilia with a 46,XXr karyotype studied with X-chromosome DNA probes

    • Simone Gilgenkrantz
    • Marie-Elisabeth Briquel
    • Isabelle Oberle

    Original Investigations Pages: 157 - 159

11. Sister chromatid exchange in highly purified human B and T lymphocytes

    • K. Miller

    Original Investigations Pages: 160 - 163

12. Deletions of the esterase D locus from a survey of 200 retinoblastoma patients

    • J. K. Cowell
    • P. Rutland
    • J. Hungerford

    Original Investigations Pages: 164 - 167

13. haplotypes identified by DNA polymorphisms at the apolipoprotein A-1 and C-III loci and hypertriglyceridaemia

    • A. Rees
    • J. Stocks
    • D. Galton

    Original Investigations Pages: 168 - 171

14. Identification of trophoblast in chorionic villi biopsy samples

    • Angela E. Covone
    • P. M. Johnson

    Short Communications Pages: 172 - 173

15. Direct estimation of the non-disjunction rate at first meiotic division in the human male

    • Marie Guichaoua
    • Segolène Ayme
    • J. -M. Luciani

    Short Communications Pages: 174 - 176

16. A new partially deficient variant in the phosphoglucomutase 1 system, PGM1^*W31

    • J. Bertrams
    • Ute Hintzen
    • Fe Barberan

    Short Communications Pages: 177 - 178

17. Variation in the frequency of sister chromatid exchanges in repeated human lymphocyte cultures

    • G. Speit
    • R. Düring
    • K. Mehnert

    Short Communications Pages: 179 - 181

18. Familial sinus node disease and degenerative myopia—a new hereditary syndrome?

    • Altan Onat

    Clinical Case Reports Pages: 182 - 184

19. 18p⁻ Syndrome: an unusual case and diagnosis by in situ hybridization with chromosome 18-specific alphoid DNA sequence

    • Svetlana G. Vorsanova
    • Y. B. Yurov
    • A. F. Tirskaia

    Clinical Case Reports Pages: 185 - 187

20. Isochromosome 15 with behaviour disorder

    • Arabella Smith
    • S. Einfeld

    Clinical Case Reports Pages: 188 - 188

21. Cytogenetic analysis of early human abortuses after preparation of chromosomes directly from chorionic villi

    • I. Hansmann
    • Iris Bartels
    • Ingrid Schübbe

    Letters to the Editors Pages: 189 - 189

22. Announcements

    Announcement Pages: 190 - 190