The aim of such testing is to reveal an early state of genetic disorders such as trisomy 21 (Down syndrome), trisomy 18 (Edward syndrome), trisomy 13 (Patau syndrome), and
monosomy X (Turner syndrome).
There are many reports with microscopic
monosomy 18p in the literature, but to our knowledge, this is the first submicroscopic deletion on 18p detected at antenatal period.
The CMA of the proband revealed two CNV: a loss of the entire chromosome X (~155 Mb) indicative of
monosomy X and a 4.69 Mb copy number loss on 1q31 .2q31 .3 (bp 192, 715, 814 to 197, 401,180) (Figure 3).
The positive predictive value in this cohort was 95.2% for trisomy 21, 93.5% for trisomy 18, 77.9% for trisomy 13, and 86.7% for
monosomy X.
No specific karyotypic abnormality is yet known to be associated with BPDCN, but six recurrent cytogenetic alterations involving 5q (72%), 12p (64%), 13q (64%), 6q (50%), 15q (43%), and
monosomy 9 (28%) have been previously proposed by Leroux et al.
Cytogenetic analyses have reported trisomy 21,
monosomy 5, and 5q deletion in AML in the context of familial platelet disorder.
For example, if a person is missing one of the chromosomes from a pair, this is called
monosomy. An example of
monosomy is Turner syndrome in which a patient is missing one chromosome and is characterized by short stature besides other difficulties.
If patients are not lost from infections, cytogenetic changes can occur such as G-CSF receptor mutations in 12% and
monosomy 7 in 50%.
Particularly
monosomy of chromosomes 14 and 22 as well as deletions of 1p are well known.
Chromosome 9p deletion syndrome (OMIM#158170) is a well-known disorder, a structural
monosomy occurring with loss of a part of 9p of varying size.
For instance,
monosomy of chromosome 3 and gain of 8q are often found in UMs.[15],[16] Multiple common driver mutations have also been identified in UM including BAP1 , EIF1AX , GNA11 , GNAQ , and SF3B1 .[17],[18],[19] Specifically, BAP1 , EIF1AX , and SF3B1 mutations are mutually exclusive during UM progression, and BAP1 mutations showed the most significant association with UM metastasis.[20] Meanwhile, epigenetic alteration such as changes in microRNAs and long ncRNAs also plays a role in the development and metastasis of UMs.[21],[22]
Figure 2b shows the expected value of the ratio for euploid,
monosomy, and trisomy samples.
