Constitutional Testing

Indications

These may include, but are not limited to:

  • A fetus, a baby, or an adult with multiple congenital abnormalities
  • Personal or family history of chromosome abnormalities
  • Suspicion of sex chromosome abnormalities
  • Infertility or history of multiple pregnancy losses
  • Developmental delay (DD), or intellectual disability (ID)
  • Autism spectrum disorder
  • Growth abnormalities
  • Spontaneous fetal demise
  • Increased risk for a chromosome abnormality, due to maternal age, family history, or personal history
  • Fetal abnormalities detected on ultrasound
  • Increased risk identified by prenatal screening techniques
  • Parental concern

Specimen types

Testing to detect chromosomal and genomic abnormalities can be performed on:

  • amniotic fluid
  • chorionic villi
  • peripheral blood
  • umbilical cord blood
  • skin biopsy
  • products of conception
  • fetal tissue
  • saliva
  • extracted DNA

See Sample Collection Instructions

Tests and Services

Available testing options include:

  • Cytogenomic Microarray Analysis (CMA) detects imbalances in the genome (copy number changes due to aneuploidy, deletions, or duplications) at high resolution and genomic regions of homozygosity (copy neutral absence of heterozygosity). This test does not detect balanced rearrangements. 
  • G-banded chromosome analysis or karyotyping (routine) detects imbalances (aneuploidy, deletions, or duplications) in the genome at low resolution. This test can detect balanced rearrangements and can be used to distinguish free trisomy from translocation-associated trisomy. In cases of familial chromosomal rearrangements a family follow-up test is available.
  • G-banded chromosome analysis or karyotyping (mosaicism): The number of cells evaluated is increased, for better detection of a second cell type present at a low level.
  • STAT IFISH (interphase fluorescence in situ hybridization) for aneuploidy using a panel of probes for chromosomes 13, 18, 21, X, and Y detects aneuploidy for these chromosomes.
  • FISH for specific microdeletion and microduplication syndromes. See list of probes below or call 206.598.4488 for additional probe availability.
  • Subtelomere FISH detects cryptic balanced and unbalanced reciprocal translocations too small to see with G-banded chromosome analysis.
  • Grow cell cutures for sendout testing: Cultures of amniocytes, chorionic villus cells, fetal tissue, or skin fibroblasts can be established in our laboratory and sent elsewhere for other types of testing.

Constitutional FISH microdeletion/duplication tests

Condition Chromosome change

22q11.2 Deletion Syndrome/DiGeorge/Velocardiofacial Syndrome

Deletion 22q11.2
22q11.2 Duplication Syndrome Duplication 22q11.2
46,XX Testicular DSD/46,XY DSD/46,XY CGD Presence/Absence SRY