A very rare case of trisomy 4q32.3-4q35.2 and trisomy 21q11.2-21q22.11 in a patient with recombinant chromosomes 4 and 21.
We report the case of a patient with a clinical phenotype consistent with Down Syndrome (DS) who has a novel karyotypic abnormality. Karyotypic analyses were performed to investigate the cause of two spontaneous abortions. A balanced translocation between chromosomes 4 and 21 was identified, along with an additional abnormal chromosome 21. We performed high-resolution banding, comparative genomic hybridization (CGH), and FISH studies in both the patient and her mother to define the abnormality and determine its origin. CGH revealed a gain in copy number on the long arm of chromosome 4, spanning at least 24.4 Mb, and a gain in copy number on the long arm of chromosome 21, spanning at least 16.2 Mb. FISH analysis using a chromosome 21 centromere probe and chromosome 4 long arm telomere (4pter) probe confirmed the origin of the marker chromosome. It has been confirmed by the State Key Laboratory of Medical Genetics of China that this is the first reported instance of the karyotype 47,XX,t(4;21)(q31.3;q11.2),+der(21)t(4;21)mat reported in the world.
Aristogenesis Center, No. 202 Hospital of PLA, Shenyang 110003, PR China.
Li-Sha
LS
Chen
Aristogenesis Center, No. 202 Hospital of PLA, Shenyang 110003, PR China.
Dan
D
Xue
Genetic disease laboratory, DongChang Maternal and Child Health Hospital, LiaoCheng 252000, PR China.
Zuo-Ming
ZM
Xi
Aristogenesis Center, No. 202 Hospital of PLA, Shenyang 110003, PR China.
Dan-Na
DN
Liu
Aristogenesis Center, No. 202 Hospital of PLA, Shenyang 110003, PR China.
Peng-Shu
PS
Zou
Aristogenesis Center, No. 202 Hospital of PLA, Shenyang 110003, PR China.
Ming
M
Ma
Aristogenesis Center, No. 202 Hospital of PLA, Shenyang 110003, PR China.
Ying
Y
Xia
Aristogenesis Center, No. 202 Hospital of PLA, Shenyang 110003, PR China.
Xia-Hui
XH
Chen
Department of Laboratory Medicine, No. 202 Hospital of PLA, Shenyang 110003, PR China.
Guang-Bin
GB
Qiu
Aristogenesis Center, No. 202 Hospital of PLA, Shenyang 110003, PR China. Electronic address: dhcao427@sina.com.
Dong-Hua
DH
Cao
D000022:Abortion, Spontaneous / Q000235:genetics; D002894:Chromosomes, Human, Pair 4 / Q000235:genetics; D055028:Comparative Genomic Hybridization; D004314:Down Syndrome / Q000235:genetics*; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008607:Intellectual Disability / Q000235:genetics*; D007621:Karyotyping; D011995:Recombination, Genetic; D014314:Trisomy / Q000235:genetics*; D055815:Young Adult
CGH; FISH; Trisomy 21q11.2–21q22.11; Trisomy 4q32.3–4q35.2