POSTNATAL

Postnatal testing is suggested for the following indications:

  • Family history of a chromosome rearrangement.
  • Family history of mental retardation.
  • Patient with:
  • -    multiple congenital abnormalities;
    -    dysmorphism;
    -    developmental delay;
    -    mental retardation;
    -    ambiguous genitalia;
    -    suspected deletion /micro deletion /duplication syndrome;
    -    short stature;
    -    abnormal secondary sexual characteristics;
    -    secondary amenorrhea or premature menopause;
    -    X-linked recessive condition in a female;
    -    features of a chromosome breakage syndrome, or other syndrome with specific cytogenetic findings.
  • Parents with prenatal diagnosis detection of a chromosome abnormality or unusual variant.
  • Couples with stillbirths with a suspected chromosome abnormality.
  • Multiple miscarriages or infertility.
  • Monitoring after bone marrow transplantation (e.g. other-sex donor in treatment of thalassaemia).
  • Environmental exposure to known mutagens or carcinogens.
  • Deviations from the normal chromosomal number or structure are detectable in 0.5% of live born babies, 10-20% of children with mental retardation and multiple congenital anomalies, and 60% of 1st trimester miscarriages; 3% of couples with infertility can be detected using standard karyotype and metaphase FISH tests.


Disease-specific FISH probes are available for:

  • Prader-Willi Syndrome/Angelman SNRPN(del 15q12-13)
  • DiGeorge Syndrome I TBX1 (del22q13.3)
  • DiGeorge Syndrome I TULPE 1 (del22q13.3)
  • DiGeorge Syndrome I N25 (del22q13.3)
  • DiGeorge Syndrome II 10p (del 10p14)
  • SRY  Yp11.2


Disease-specific FISH probes available on request in consultation with clinicians:

  • 1p36
  • Wolf-Hirschhorn WSHCR 4p16.3
  • Cri du Chat  EGR1  5p15.2
  • Sotos NSD1  5q35
  • Williams ELN 7q11.23
  • Saethre-Chotzen 7p21.12
  • CHARGE 8q12.1Retinoblastoma  RB1 13q
  • Smith Magenis (FLI1, RAI1) 17p11.2
  • Miller Dieker 17p13.3
  • Angelman UBE3A 15q11q13
  • Prader-Willi  GABRB314 15q11q13
  • Rubinstein-Taybi 16p13.3
  • Alagille (JAG1) 20p12
  • Neurofibromatosis NF-1 17q11.24
  • Kallman KAL1 Xp22.3
  • Steroid Sulfatase Deficiency  Xp22.3
  • SHOX Xp22
  • XIST Xq13.2
  • Acrocentric p-arms Probe Combination


Counselling and informed consent are recommended for genetic testing.