Editing Choroid plexus cyst (section)

==Genetic causes==
There is a possible association between ultrasound-detected fetal CPCs and [[Trisomy 18]].<ref name="pmid17357350">{{cite journal |last1=Hurt |first1=K |last2=Sottner |first2=O |last3=Záhumenský |first3=J |last4=Halaska |first4=M |last5=Krcmár |first5=M |last6=Driák |first6=D |last7=Zmrhalová |first7=B |last8=Rakovicová |first8=I |title=Cysty chorioidálního plexu a riziko trizomie 18. Modifikace ke vztahu k věku a markerům |trans-title=Choroid plexus cysts and risk of trisomy 18. Modifications regarding maternal age and markers |language=Czech |journal=Česká Gynekologie |date=January 2007 |volume=72 |issue=1 |pages=49–52 |pmid=17357350 |url=https://www.cs-gynekologie.cz/casopisy/ceska-gynekologie/2007-1/cysty-choroidalniho-plexu-a-riziko-trizomie-18-modifikace-ve-vztahu-k-veku-a-markerum-3505 }}</ref><ref name="pmid17206726">{{cite journal |last1=Papp |first1=Csaba |last2=Ban |first2=Zoltan |last3=Szigeti |first3=Zsanett |last4=Csaba |first4=Akos |last5=Beke |first5=Artur |last6=Papp |first6=Zoltan |title=Role of second trimester sonography in detecting trisomy 18: A review of 70 cases |journal=Journal of Clinical Ultrasound |date=February 2007 |volume=35 |issue=2 |pages=68–72 |doi=10.1002/jcu.20290 |pmid=17206726 |s2cid=23836946 }}</ref>  It is not correlated to the presence of Trisomy 21 ([[Down syndrome]]).<ref name="pmid18085527">{{cite journal |last1=Dagklis |first1=T. |last2=Plasencia |first2=W. |last3=Maiz |first3=N. |last4=Duarte |first4=L. |last5=Nicolaides |first5=K. H. |title=Choroid plexus cyst, intracardiac echogenic focus, hyperechogenic bowel and hydronephrosis in screening for trisomy 21 at 11 + 0 to 13 + 6 weeks |journal=Ultrasound in Obstetrics & Gynecology |date=February 2008 |volume=31 |issue=2 |pages=132–135 |doi=10.1002/uog.5224 |pmid=18085527 |doi-access=free }}</ref><ref>{{cite journal |last1=Bromley |first1=B. |last2=Lieberman |first2=E. |last3=Benacerraf |first3=B. R. |title=Choroid plexus cysts: not associated with Down syndrome |journal=Ultrasound in Obstetrics and Gynecology |date=1 October 1996 |volume=8 |issue=4 |pages=232–235 |doi=10.1046/j.1469-0705.1996.08040232.x |pmid=8916374 |s2cid=10202905 }}</ref> Therefore, [[genetic counseling]] is often recommended to provide more information about fetal CPCs, to answer questions and concerns, and to outline available options such as [[amniocentesis]] or a blood test from the mother.<ref name="pmid17357350"/>

Generally the risks are very low if there are no other risk factors. If no additional abnormalities are detected by a thorough "level II" ultrasound, the likelihood the fetus has trisomy 18 is very low.{{fact|date=June 2020}}

A meta-analysis of 8 studies between 1990 and 2000 with choroid plexus cysts that were identified in second-trimester (an incidence of 1.2%). The incidence of the cysts in women younger than 35 was 1% (n=1017). The study found no cases of trisomy 18 in fetuses with cysts whose mother was younger than 35. The study concluded that "there is no evidence that detection of isolated choroid plexus cyst in women who are <35 years of age increases the risk of trisomy 18".<ref>{{cite journal |last1=Demasio |first1=Kafui |last2=Canterino |first2=Joseph |last3=Ananth |first3=Cande |last4=Fernandez |first4=Carlos |last5=Smulian |first5=John |last6=Vintzileos |first6=Anthony |title=Isolated choroid plexus cyst in low-risk women less than 35 years old |journal=American Journal of Obstetrics and Gynecology |date=November 2002 |volume=187 |issue=5 |pages=1246–1249 |doi=10.1067/mob.2002.127463 |pmid=12439513 }}</ref>

Other factors which may have a bearing on the baby's chances of developing chromosome problems include:{{fact|date=June 2020}}
* mother's age at the expected date of delivery
* the results of serum screening; XAFP [[triple test]]ing or quad screening
* evidence of other "fetal findings" seen at the time of the ultrasound that may suggest a chromosome problem