Prenatal Screening in first trimester.
早孕期染色體疾病檢查: 唐氏綜合症.

產前的篩檢項目中,染色體檢查是相當重要的一項,尤其是高齡產婦或是流產高發生群孕婦。
Why do we need Prenatal Screening in the first trimester?

什麼是染色體?What is chromosome?

染色體是儲存人類遺傳訊息「基因」的結構, 正常嬰兒細胞染色體共有23對46條染色體.,分別來自父母雙方.
Chromosomes are a DNA, it dictates who we are, how we look like and our personality. Humans have 23 pairs of chromosomes, one set from each parent.

前22對叫做體染色體, 最後一對為性染色體(sex chromosomes),乃因決定人類性別. 正常男性帶著XY性染色體,女性為XX

Our 23rd pair of chromosomes dictates if we are male are female. XX being female, XY being male.

染色體異常 Chromosomes abnormality

染色體疾病的分類

染色體疾病可分為三大類:即數目異常、結構異常及混合有兩種或兩種以上細胞核型的拼湊型異常。

If there is any mismatch, addition or deletion in any of the 23 pairs chromosomes, mothers may have a miscarriage or infant may be born to have genetic defects, growth retardation or shorter lifespan.

「唐氏綜合症」(T21) 的嬰兒於在第21號染色體多一條所致,故這些嬰兒有47條,影響他們的外觀、身體及智力發展. 大約700人之中有一名會有唐氏綜合症。

Down Syndrome occurs when there is an extra chromosome 21.

除了第21對染色體,第13 「巴陶氏症」和18 「愛德華氏綜合症」對亦常見出現出錯問題,惟對胎兒發展影響更大,此類孩子通常難以生存。

艾德華氏症
艾德華氏症(Edwards syndrome)即三染色體18症,發生率約為每7,000個活產當中會出現一例,女性患者遠多於男性

Edwards Syndrome occurs when there is an extra chromosome 18.

巴陶氏症
巴陶氏症(Patau syndrome)即三染色體13症,
此症的發生率約為每20,000個活產兒會出現一例,由於13號染色體帶有較多的基因數,因此13號三染色體症會造成相當嚴重的傷害,其平均壽命約只有4~6個月,絕大多數的患兒在三歲以前均會夭折。

Patau syndrome occurs when there is an extra 13 chromosome.

透納氏症
透納氏症(Turner’s syndrome)又稱為X單染色體症(monosomy X), 這是唯一失去一整個染色體仍能存活的疾病。即使如此,大多數的X單染色體症胎兒在懷孕早期便自然流產或胎死腹中。

Turner’s Syndrome occurs when one X chromosome is missing.
篩查測試去計算胎兒染色體綜合症的風險(或機會)

產前的篩檢項目中,染色體檢查是相當重要的一項,尤其是高齡產婦或是流產高發生群孕婦。

Therefore, it is important to have prenatal screening during the 9th-12th weeks of pregnancy.
Please watch the next video to find out what prenatal screening suits you.

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Kayi

2018-08-16T10:22:49+00:00