What is Down syndrome?
Down syndrome (sometimes called Down’s syndrome) is a condition in which a child is born with an extra copy of their 21st chromosome — hence its other name, trisomy 21. This causes physical and mental developmental delays and disabilities.
Many of the disabilities are lifelong, and they can also shorten life expectancy. However, people with Down syndrome can live healthy and fulfilling lives. Recent medical advances, as well as cultural and institutional support for people with Down syndrome and their families, provides many opportunities to help overcome the challenges of this condition.
在所有繁殖的情况下，父母双方都将其基因传递给孩子。这些基因在染色体中进行。当婴儿的细胞发展时，每个细胞应该接受23对染色体，总共46次染色体。一半的染色体来自母亲，一半来自父亲。
在患有唐氏综合症的儿童中，其中一条染色体不正确分离。宝宝结束了三个副本，或额外的部分拷贝，染色体21，而不是两个。这种额外的染色体会导致大脑和物理特征的问题产生问题。
根据这一点全国唐氏综合征社会（NDSS）在美国的700名婴儿中约有1个患有唐氏综合症。这是美国最常见的遗传障碍。
唐氏综合症有三种类型：
三术21.
三术21.means there’s an extra copy of chromosome 21 in every cell. This is the most common form of Down syndrome.
Mosaicism
Mosaicism当一个孩子出生时，在某些但不是所有的细胞中出生时患有额外的染色体。马赛克唐氏综合征的人往往具有比三元图21的症状更少。
易位
In this type of Down syndrome, children have only an extra part of chromosome 21. There are 46 total chromosomes. However, one of them has an extra piece of chromosome 21 attached.
某些父母有更大的机会给birth to a child with Down syndrome. According to the Centers for Disease and Prevention, mothers aged 35 and older are
研究表明，父亲年龄也有效果。一2003年的研究found that fathers over 40 had twice the chance of having a child with Down syndrome.
Other parents who are more likely to have a child with Down syndrome include:
- 有一个唐氏综合征的家族史的人
- people who carry the genetic translocation
重要的是要记住，这些因素中的任何一个都意味着你肯定会有一个患有唐氏综合症的婴儿。然而，统计上和大量的人口，他们可能会增加你可能的机会。
虽然通过筛选在怀孕期间筛查携带患有唐氏综合症的患者的可能性，但您不会遇到患有唐氏综合症的孩子的任何症状。
出生时，患有唐氏综合症的婴儿通常具有一定的特征标志，包括：
- 平面面部特色
- 耳朵耳朵
- 短脖子
- bulging tongue
- 向上倾斜的眼睛
- 非典型的耳朵
- poor muscle tone
一个infant with Down syndrome can be born an average size, but will develop more slowly than a child without the condition.
患有唐氏综合症的人通常具有一定程度的发育残疾，但它通常很温和到中度。心理和社会发展延误可能意味着孩子可以有：
- 冲动的行为
- poor judgment
- 注意力短暂
- 慢慢学习能力
医疗并发症往往伴随着唐氏综合症。这些可能包括：
- congenital heart defects
- 听力损失
- 视力不佳
- 白内障（云眼睛）
- 髋关节问题，如脱臼
- leukemia
- chronic constipation
- sleep apnea（睡眠期间中断呼吸）
- 失智（思想和记忆问题）
- hypothyroidism(low thyroid function)
- obesity
- late tooth growth, causing problems with chewing
- 阿尔茨海默氏病later in life
People with Down syndrome are also more prone to infection. They may struggle withrespiratory infections那尿路感染那and皮肤感染。
筛查唐氏综合症是作为美国产前护理的常规部分。如果你是一个超过35岁的女性，你的宝宝的父亲已经超过40岁，或者有一个唐氏综合症的家族史，你可能想要获得评估。
First trimester
一个ultrasound evaluationand blood tests can look for Down syndrome in your fetus. These tests have a higher false-positive rate than tests done at later pregnancy stages. If results aren’t normal, your doctor may follow up with an amniocentesis after your 15th week of pregnancy.
第二个三个月
超声波和四重标记屏（QMS）测试可以帮助识别脑和脊髓中的综合征和其他缺陷。该试验在怀孕15到20周之间进行。
If any of these tests aren’t normal, you’ll be considered at high risk for birth defects.
额外的产前试验
您的医生可能会订购其他测试以检测宝宝的综合症。这些可能包括：
- 羊膜穿刺术。你的医生需要一个sample of amniotic fluidto examine the number of chromosomes your baby has. The test is usually done after 15 weeks.
- 绒毛膜绒毛采样（CVS）。Your doctor willtake cells from your placenta分析胎儿染色体。该测试是在怀孕的第9和第14周之间完成的。它可以增加你流产的风险，但根据梅奥诊所，只能小于1 percent。
- 经皮脐血液采样（PUB或肠腔穿孔孔）。Your doctor will take blood from the umbilical cord and examine it for chromosomal defects. It’s done after the 18th week of pregnancy. It has a higher risk of miscarriage, so it’s performed only if all other tests are uncertain.
有些女性因为风险而选择不接受这些测试流产。They’d rather have a child with Down syndrome than lose the pregnancy.
在出生时进行测试
出生时，你的医生会：
- 对宝宝进行体检
- order a blood test called a核型确认唐氏综合症
There’s no cure for Down syndrome, but there’s a wide variety of support and educational programs that can help both people with the condition and their families. Then只是一个寻找全国各节目的一个地方。
Available programs start with interventions in infancy.Federal law要求各国为合格家庭提供治疗计划。在这些方案中，特殊教育教师和治疗师将帮助您的孩子学习：
- sensory skills
- social skills
- self-help skills
- 运动技能
- 语言和认知能力
唐氏综合症的儿童经常符合与年龄相关的里程碑。然而，他们可能比其他孩子更慢地学习。
无论智力能力如何，学校都是一个孩子生命的重要组成部分。公共和私立学校支持患有唐氏综合症及其家庭的人，综合教室和特殊教育机会。学校教育允许有价值的社会化，帮助学生患上综合症建立重要的生活技能。
The lifespan for people with Down syndrome has improved dramatically in recent decades. In
If you’re raising a child with Down syndrome, you’ll need a close relationship with medical professionals who understand the condition’s unique challenges. In addition to larger concerns — like heart defects and leukemia — people with Down syndrome may need to be guarded from common infections such as colds.
患有唐氏综合症的人寿更长时间，更丰富的生活现在比以往任何时候都更多。虽然他们经常面对一系列独特的挑战，但它们也可以克服那些障碍和茁壮成长。建立经验丰富的专业人士和理解家庭和朋友的强大支持网络对于患有唐氏综合症及其家庭的人们的成功至关重要。
看看全国唐氏综合征社会和National Association for Down Syndromefor help and support.