1. Pure trisomy 17p in 60% of cells

   • F. Shabtai
   • A. Shalev
   • E. Elian

   Original Investigations Pages: 263 - 268

2. Interstitial deletion 13q syndromes: A report on two unrelated patients

   • M. Serena-Lungarotti
   • Anna Calabro
   • B. Dallapiccola

   Original Investigations Pages: 269 - 274

3. An uncommon phenotypical variant in the Shereshevsky-Turner syndrome

   • I. G. Dzenis
   • N. N. Antipina

   Original Investigations Pages: 275 - 279

4. Sister chromatid exchanges in cultured peripheral lymphocytes from twins

   • C. Pedersen
   • Eva Oláh
   • U. Merrild

   Original Investigations Pages: 281 - 294

5. Nucleolar organizers in human oocytes at meiotic prophase I, studied by the silver-NOR method and electron microscopy

   • M. Hartung
   • C. Mirre
   • A. Stahl

   Original Investigations Pages: 295 - 308

6. Mutagenic effects of isonicotinic acid hydracide in Fanconi's anemia

   • Traute M. Schroeder
   • Christine Stahl-Maugé

   Original Investigations Pages: 309 - 321

7. On the nature of sickle-cell disease in the Arabian Peninsula

   • M. A. F. El-Hazmi

   Original Investigations Pages: 323 - 335

8. Calculating genetic risk figures using a programmable pocket calculator

   • G. R. Stalder

   Original Investigations Pages: 337 - 341

9. Frequency of sister chromatid exchanges in cigarette smokers

   • P. Bala Krishna Murthy

   Short Communications Pages: 343 - 345

10. Partial deficiency of red cell 6-phosphogluconate dehydrogenase: A family study

    • F. Ajmar
    • G. Lamedica
    • A. Campostano

    Short Communications Pages: 347 - 351

11. Biochemistry and genetics of gangliosidoses

    • K. Sandhoff
    • H. Christomanou

    Errata Pages: 353 - 353