In the clinical cytogenetics laboratory several methods are utilized to detect chromosome abnormalities that may confer a phenotypic or reproductive impact. The laboratory performs high-resolution chromosome analysis on peripheral blood and also analysis of bone marrow samples and tissue specimens. Other tests also include chromosome breakage, fluorescence in situ hybridization (FISH), and microarray analysis. Cytogenetic analysis is performed by certified clinical laboratory specialists and reviewed by a certified Ph.D. clinical cytogeneticist.

Indications for cytogenetic analysis:

Family history of chromosome anomaly

Recurrent spontaneous abortions

Infertility

Still birth and neonatal deaths

Fetal anomalies detected with ultrasound

Mental retardation

Dysmorphic features

Females with primary or secondary amenorrhea

Ambiguous genitalia

Hematologic disorders, such as leukemia

Ataxia telangiectasia and Fanconi's anemia

Hours of Operation:

Monday - Friday: 8:30 am to 5:30 pm EST

The lab also has limited weekend hours.

LABORATORY TESTS

Bone Marrow Chromosome Analysis

Bone marrow aspirate or peripheral blood, with blasts present, are cultured without mitogens to detect acquired abnormalities related to the leukemic process. These abnormalities can elucidate the diagnosis and be of prognostic significance.

Peripheral Blood High Resolution Chromosome Analysis

Lymphocytes are stimulated with mitogens and synchronized to yield elongated chromosomes. These long chromosomes permit high resolution analysis to detect more subtle abnormalities.

Fluorescence in situ hybridization (FISH) Analysis

Fluorescence in situ hybridization (FISH) is used to detect alterations in specific chromosomal regions from metaphase spreads and/or interphase nuclei. These probes show specific changes, such as amplifications, deletions, or translocations of specific genes, loci, or chromosomal regions. FISH may be performed on peripheral blood, bone marrow, fibroblast, or lymphoblast cultures.

Chromosomal Breakage Analysis

Peripheral blood samples are treated with DEB (diepoxybutane) or X-irradiated to induce breakage in individuals with suspected diagnosis of Fanconi's anemia or Ataxia telangiectasia, respectively. The frequency of breaks is compared to a normal control run in parallel and also to our database of positive and negative individuals.

Array SNP-based Analysis

The 610 Quad Illumina array contains probes targeting single nucleotide polymorphisms (SNPs) and non-polymorphic markers. Both types of probes are utilized to detect copy number changes (CNC), including deletions, duplications, and unbalanced rearrangements. SNP probes provide allelic information and are used to detect copy number neutral loss of heterozygosity (LOH) or uniparental disomy (UPD). Two genotyping measurements, normalized intensity and allelic ratios, are performed utilizing the KaryoStudio software and allow the identification of CNC and LOH/UPD. The array will not identify balanced rearrangements, including reciprocal and Robertsonian translocations, insertions or inversions, nor will it detect point mutations.