single gene disorders Mendelian disorders autosomal dominant autosomal

단일유전자질환 (single gene disorders, Mendelian disorders) 보통염색체 우성유전 (autosomal dominant) 보통염색체 열성유전 (autosomal recessive) Achondroplasia α 1 -Antitrypsin deficiency Acute intermittent porphyria Congenital adrenal hyperplasia Adult polycystic kidney disease Cystic fibrosis Antithrombin III deficiency Gaucher disease BRCA 1 and BRCA 2 breast cancer Hemochromatosis Ehlers-Danlos syndrome Homocystinuria Familial adenomatous polyposis Phenylketonuria Familial hypercholesterolemia Sickle cell anemia Hereditary hemorrhagic telangiectasia Tay-Sachs disease Hereditary spherocytosis Thalassemia syndromes Huntington disease Wilson disease Hypertrophic obstructive cardiomyopathy Long QT syndrome Marfan syndrome Myotonic dystrophy Neurofibromatosis type 1 and 2 Tuberous sclerosisvon Willebrand disease

X-linked Androgen insensitivity syndrome Chronic granulomatous disease Color blindness Fabry disease Fragile X syndrome Glucose-6 -phosphate deficiency Hemophilia A and B Hypophosphatemic rickets Muscular dystrophy—Duchenne and Becker Ocular albinism type 1 and 2

염색체 검사법 세포분열중기(metaphase)의 세포 혈액이나 양수세포는 일정기간 배양이 필요 검사법 • 띠염색(banding) • 형광제자리부합법(fluorescent in situ hybridization) • Southern blotting • Polymerase chain reaction (PCR) • 비교유전체부합법(comparative genomic hybridization)

21세염색체 증후군(trisomy 21 syndrome)

염색체의 구조적 이상 1. 염색체 전위 (chromosomal translocations) 상호전위 (reciprocal translocations) 로버슨형전위 (Robertsonian translocation) 2. 염색체 역전 (chromosomal inversions) 3. 염색체 결손 (chromosomal deletions) 4. 고리염색체 (ring chromosome) 5. 염색체 섞임증 (chromosomal mosaicism)

비멘델 유전 1. 삼핵산반복질환 (trinucleotide repeat disorder) 유약X증후군 (fragile X syndrome) 근육긴장퇴행위축 (myotonic dystrophy) 헌팅턴병 (Huntington disease) 2. 각인 (imprinting) 3. 단부모이체증 (uniparental disomy) 4. 사립체유전 (mitochondrial inheritance)

염색체 이상 임신의 고위험군 Singleton pregnancy and maternal age older than 35 at delivery a Dizygotic twin pregnancy and maternal age older than 31 at delivery Previous autosomal trisomy birth Previous 47, XXX or 47, XXY birth Patient or partner is carrier of chromosome translocation Patient or partner is carrier of chromosomal inversion History of triploidy Some cases of repetitive early pregnancy losses Patient or partner has aneuploidy Major fetal structural defect by sonography a. All women, regardless of age, should have the option of invasive testing (American College of Obstetricians and Gynecologists).

신경관결손 Neural tube defects (NTDs)

주수에 따른 alpha-fetoprotein (AFP)의 농도

신경관결손의 선별검사 (AFP) higher levels of AFP in maternal serum and amnionic fluid

Amniocentesis to determine the amnionic fluid AFP level an assay for acetylcholinesterase if positive, diagnostic of a NTD

Some Conditions Associated with Abnormal Maternal Serum Alpha-Fetoprotein Concentrations Elevated Levels Underestimated gestational age Urinary obstruction Multifetal gestation Fetal death Renal anomalies—polycystic kidneys, renal agenesis Neural-tube defects Congenital nephrosis Gastroschisis Osteogenesis imperfecta Omphalocele Congenital skin defects Low maternal weight Cloacal exstrophy Pilonidal cysts Chorioangioma of placenta Esophageal or intestinal obstruction Placental abruption Liver necrosis Preeclampsia Cystic hygroma Low birthweight Sacrococcygeal teratoma Maternal hepatoma or teratoma Oligohydramnios

Some Conditions Associated with Abnormal Maternal Serum Alpha-Fetoprotein Concentrations Low Levels Obesitya Diabetesa Chromosomal trisomies Gestational trophoblastic disease Fetal death Overestimated gestational age a. Adjustments in formula used to calculate risk.

다운증후군 Down syndrome and other aneuploidies

임신 제 1삼분기의 다운증후군 선별검사 1. Nuchal translucency (NT, 태아목덜미투명대)≥ 3. 5 mm 2. Maternal serum marker (PAPP-A, h. CG)

Singleton Gestation—Maternal Age-Related Risk for Down Syndrome and Any Aneuploidy at Midtrimester and at Term Down Syndrome Any Aneuploidy Maternal Age Midtrimester Term 35 1/250 1/384 1/132 1/204 36 1/192 1/303 1/105 1/167 37 1/149 1/227 1/83 1/130 38 1/115 1/175 1/65 1/103 39 1/89 1/137 1/53 1/81 40 1/69 1/106 1/40 1/63 41 1/53 1/81 1/31 1/50 42 1/41 1/64 1/25 1/39 43 1/31 1/50 1/19 1/30 44 1/25 1/38 1/15 1/24 45 1/19 1/30 1/12 1/19

침습적 산전 진단 1. 임신중기 양수천자 (second-trimester amniocentesis) 2. 용모막융모생검 (chorionic villus sampling, CVS) 3. 경피제대혈채취 (cordocentesis, percutaneous umbilical cord blood sampling, PUBS) 4. 태아조직 생검 (fetal tissue biopsy) 5. 착상 전 유전진단 (preimplantation genetic diagnosis) 6. 모체순환내의 태아세포 (fetal cells in the maternal circulation)