Home > D. Systemic pathology > Genetic and developmental anomalies > Chromosomal diseases > chromosomal diseases

chromosomal diseases

Monday 5 April 2004

It is estimated that 50% of spontaneous abortuses during the early months of gestation have a demonstrable chromosomal abnormality; there are, in addition, numerous smaller detectable errors and many others still beyond our range of identification. About 1% of all newborn infants possess a gross chromosomal abnormality.

Types

- numerical chromosomal anomalies

  • ploidy anomalies (aneuploidy)
    • triploidy
    • tetraploidy
  • autosomal monosomies
  • autosomal trisomies
    • trisomy 21 (Down syndrome)
    • trisomy 13
    • trisomy 18
    • trisomy 8
    • trisomy 9
  • autosomal tetrasomies

- structural chromosomal anomalies

  • deletions
    • chromsome 13 deletion
    • 18q- syndrome (del18q)
    • 18p- syndrome (del18p)
    • 4p- syndrome (del4p) (Wolf-Hischhorn syndrome)
    • 5p- syndrome (del5p) (cat-cry syndrome)
    • 11p- syndrome (del11p)
    • 17p- syndrome (Miller-Dieker syndrome)
    • isodicentric 22 (22pter-q11) (Schmid-Fraccaro syndrome)
    • 21q- syndrome (del21q)
    • 22q- syndrome (del22q)

- chromosomal duplications

- chromosomal recombinaisons

  • recombinant chromsome 8 syndrome (RC8S)

- chromosomal translocations

- ring chromosomes

- gonosomal anomalies

  • monosomy X (45,X) (Turner syndrome)
  • 47,XXY
  • 47,XXX
  • 47,XYY

- mosaicism