Indications for chromosome analysis in clinical genetics

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Chromosomal analysis[edit | edit source]

  • prenatal
  • postnatal

Indications for prenatal analysis of chromosomes[edit | edit source]

  • advanced maternal age
  • higher than 35 ys in the date of delivery (increased risk of chromosomal aneuploidies, namely M. Down)
  • positive screening of congenital anomalies (1st or 2nd trimester maternal serum screening test + increased NT - higher risk of chromosomal abnormalities)
  • positive family history
  • affected child/fetus in previous pregnancy (with chromosomal abnormality)
  • parent - carrier of balanced chromosomal aberration (e.g. translocation)
  • patological or atypical ultrasound finding (IUGR – intrauterine growth retardation, microcephaly, hyperechogenic bowel, hydronephrosis, Fallot tetralogy, club foot, polyhydramnios/oligohydramnios, hygroma colli cysticum,...)
  • important for differential diagnosis (ultrasound finding could be solitary – usually without chromosomal abnormality or syndromologic – in many cases caused by chromosomal abnormality)
  • others (e.g. mother after chemotherapy, in vitro fertilisation pregnancy, …)

Indications for postnatal analysis of chromosomes[edit | edit source]

  1. children:
    • craniofacial dysmorphy (flat occiput, epicantus, hypertelorism, cleft lip, cleft palate, malformed ears, craniosynostosis, macroglossia,...)
    • congenital anomalies (heart defects, cryptorchism, NTD – neural tube defects, urogenital defects, agenesis corpus callosum,...)
    • psychomotoric retardation
    • developmental delay, failure to thrive
    • growth retardation, short stature
    • hypotonia
  2. puberty:
    • amenorhoea
    • gynecomastia
    • developmental defects of secondary sexual features
  3. adults:
    • infertility/sterility
    • recurrent spontaneous abortions
    • abnormal spermiogram in men
    • positive family history (reproduction loss, affected child, chromosomal aberration in relatives,…)
    • gamete donors