De novo 16p13.11 microdeletion identified by high-resolution array CGH in a fetus with increased nuchal translucency.
OBJECTIVE
We investigated the application of high-resolution microarray-based comparative genomic hybridisation (array CGH) on a fetus showing increased nuchal translucency (NT).


METHODS
Case study.


METHODS
Tertiary referral obstetrics unit.


METHODS
Pregnant woman attended the antenatal clinic.


METHODS
Conventional karyotyping and genetic test was carried out for the alpha-globin gene. High-resolution array CGH using the high-density 244K Agilent microarray was performed on fetal blood sample by cordocentesis to investigate the possibility of any genomic imbalance.


METHODS
Detection of chromosomal abnormality.


RESULTS
Karyotyping analysis showed 46,XY. Molecular genetic diagnosis confirms the fetus has Hb-H constant spring disease but cannot explain the increased NT to 3.2 mm. Array CGH analysis discovered a 1.32-Mb microdeletion on chromosome 16p13.11. Deletion at 16p13.11 has been implicated to predispose to autism and/or mental retardation. Baby was delivered at 40 weeks of gestation, and follow up was carried out at 3 months of age without sign of mental retardation/developmental delay.


CONCLUSIONS
This case study demonstrated that array CGH can accurately calibrate the size and identify de novo interstitial chromosome imbalances. However, the presence of chromosome copy variants with unknown clinical significance currently limits its wider scale application in prenatal diagnosis and needs further investigations.
Law
L W
LW
Fetal Medicine Unit, Department of Obstetrics and Gynaecology, Prince of Wales Hospital, Li Ka Shing Institute of Health Sciences, The Chinese University of Hong Kong, Hong Kong, SAR.
Lau
T K
TK
Fung
T Y
TY
Leung
T Y
TY
Wang
C C
CC
Choy
K W
KW
D000328:Adult; D001321:Autistic Disorder / Q000235:genetics; D002869:Chromosome Aberrations; D002885:Chromosomes, Human, Pair 16; D055028:Comparative Genomic Hybridization; D005260:Female; D017353:Gene Deletion; D020022:Genetic Predisposition to Disease; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008607:Intellectual Disability / Q000235:genetics; D007621:Karyotyping; D048208:Nuchal Translucency Measurement; D020411:Oligonucleotide Array Sequence Analysis; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011296:Prenatal Diagnosis / Q000379:methods*; D055542:alpha-Globins / Q000235:genetics
D055542:alpha-Globins