nyu school of medicine cytogenetics lecture 2 mary ann perle, ph.d
Post on 20-Dec-2015
249 views
TRANSCRIPT
NYU SCHOOL OF MEDICINE
CYTOGENETICS LECTURE 2
Mary Ann Perle, Ph.D.
TRANSLOCATION
46,XX,t(4;10)(p14;q11.2)
FEMALE WITH A RECIPROCAL TRANSLOCATION BETWEEN THE SHORT ARMS OF A #4 AND LONG
ARMS OF A #10
46,XY,der(10)t(4;10)(p14;q11.2)mat
ABNORMAL MALE: UNBALANCED KARYOTYPE WITH AN ABERRANT #10 DERIVED FROM A MATERNAL 4q;10q
TRANSLOCATION
Fre
qu
ency
/ 10
00 B
irth
s
Frequency of Down syndrome at birth related to maternal age.
Maternal Age
TEST
TEST
35 y.o.
40 y.o.
Simian crease
Fig. 2.27a-c. Children with Down syndrome. a. European, b. Afro-American, c. Asian. The common features of Down syndrome are more impressive than the racial differences. Courtesy of Dr. T.M. Schroeder-Kurth
47,XX,+18
ABNORMAL FEMALE WITH TRISOMY 18
Fig. 3-6. Two infants illustrating craniofacial characteristics of trisomy 18 (prominent occiput, low-set malformed ears and small chin).
47,XX,+13
ABNORMAL FEMALE WITH TRISOMY 13
69,XXX
ABNORMAL FEMALE WITH CHROMOSOMAL
TRIPLOIDY
Fluorescence In Situ Hybridization
A molecular tool used to detect genetic abnormalities
A DNA probe finds target sequences on chromosomal DNA as they are found in cells – “in the original place”
0000016441.jpg
PARTIAL
Normal X Ring “Dot”
Chromosome 2 = Red
X chromosome = Green
Angelman Syndrome (deletion 15q11-q13)
q11q13
Angelman Syndrome: 15q11probe
FISH for IgH/14q32 (dual color breakapart probe)
Two fusion signals indicating no rearrangement of IgH locus
NORMAL BONE MARROW
FISH for IgH/14q32 Split signal indicating positive rearrangement
of IgH locus
ABNORMAL BONE MARROW