Sorted By Test Name - Mayo Medical Laboratories

FP73
88541
Interpretation: The presence of 1p deletion and combined 1p and 19q deletion supports a diagnosis of
oligodendroglioma may indicate that the patient may respond to chemotherapy and radiation therapy. The
presence of gain of chromosome 19 supports a diagnosis of high-grade astrocytoma (glioblastoma
multiforme). A negative result does not exclude a diagnosis of oligodendroglioma or high-grade
astrocytoma. A tumor is considered to have 1p or 19q deletion when the 1p probe to 1q probe ratio
(1p/1q) or the 19q probe to 19p probe ratio (19q/19p) is 1.30. A tumor is considered to have chromosome 1 or 19 gain when the
percentage of nuclei with > or =3 signals is >20%. A normal 1p/1q ratio is 0.9-1.05 and a normal 19q/19 p
ratio is 0.93-1.02.(7)
Reference Values:
An interpretive report will be provided.
Clinical References: 1. James CD, Smith JS, Jenkins RB: Genetic and molecular basis of primary
central nervous system tumors. In Cancer in the Nervous System. Edited by VA Levine. New York,
Oxford University Press, 2002, pp 239-251 2. Cairncross JG, Ueki K, Zlatescu MC, et al: Specific genetic
predictors of chemotherapeutic response and survival in patients with anaplastic oligodendrogliomas. J
Natl Cancer Inst 1998 October 7;90(19):1473-1479 3. Ino Y, Zlatescu MC, Sasaki H, et al: Long survival
and therapeutic responses in patients with histologically disparate high-grade gliomas demonstrating
chromosome 1p loss. J Neurosurg 2000 June;92(6):983-990 4. Smith JS, Tachibana I, Passe SM, et al:
PTEN mutation, EGFR amplification, and outcome in patients with anaplastic astrocytoma and
glioblastoma multiforme. J Natl Cancer Inst 2001 August 15;93(16):1246-1256 5. Smith JS, Alderete B,
Minn Y, et al: Localization of common deletion regions on 1p and 19q in human gliomas and their
association with histological subtype. Oncogene 1999 July 15;18(28):4144-4152 6. Smith JS, Perry A,
Borell TJ, et al: Alterations of chromosome arms 1p and 19q as predictors of survival in
oligodendrogliomas, astrocytomas, and mixed oligoastrocytomas. J Clin Oncol 2000
February;18(3):636-645 7. Jenkins RB, Curran W, Scott CB, et al: Pilot evaluation of 1p and 19q
deletions in anaplastic oligodendrogliomas collected by a national cooperative cancer treatment group.
Am J Clin Oncol 2001 October;24(5):506-508 8. Burger PC: What is an oligodendroglioma? Brain Pathol
2002;12:257-259
1p36.3 Microdeletion Syndrome, FISH
Clinical Information: Chromosome 1p microdeletion syndrome is associated with a spectrum of
dysmorphic features and mental retardation. The syndrome can be suspected in overweight patients with
mental retardation, heart defects, and finger abnormalities. Facial features include microcephaly (small
head), short neck, malformed ears, and small deep-set eyes. The phenotype is variable and depends on the
size of the deletion. FISH studies are highly specific and do not exclude other chromosome abnormalities.
For this reason, we recommend that patients suspected of having 1p microdeletion syndrome also have
conventional chromosome studies (CMS/8696 Chromosome Analysis, for Congenital Disorders, Blood)
performed to rule out other chromosome abnormalities or translocations.
Useful For: Aids in the diagnosis of 1p microdeletion syndrome, in conjunction with CMS/8696
Chromosome Analysis, for Congenital Disorders, Blood Detecting cryptic translocation involving 1p36.3
that are not demonstrated by conventional chromosome studies
Interpretation: Any individual with a normal signal pattern (2 signals) in each metaphase is
considered negative for a deletion in the region tested by this probe. Any patient with a FISH signal
pattern indicating loss of the critical region will be reported as having a deletion of the region tested by
this probe. This is consistent with a diagnosis of 1p microdeletion syndrome.
Reference Values:
An interpretive report will be provided.
Clinical References: 1. Shapira SK, McCaskill C, Northrup H, et al: Chromosome 1p36 deletions:
the clinical phenotype and molecular characterization of a common newly delineated syndrome. Am J
Hum Genet 1997;61:642-650 2. Hielstedt HA, Ballif BC, Howard LA, et al: Physical map of 1p36,
placement of breakpoints in monosomy 1p36, and clinical characterization of the syndrome. Am J Hum
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