Genetic Flashcards
(60 cards)
- What are the key features of Edwards syndrome (Trisomy 18)?
Trisomy 18: IUGR, clenched fists, rocker-bottom feet, micrognathia, VSD, poor prognosis
- Karyotype: 47,XX/XY+18
- What are the features of Klinefelter syndrome (47,XXY)?
Features: Tall stature, small testes, gynecomastia, learning difficulties, infertility
- Karyotype: 47,XXY
- How is Turner syndrome diagnosed?
Diagnosis: Karyotyping
- May be suspected with short stature and delayed puberty in girls
- What are the medical complications of Turner syndrome?
Complications: Coarctation of aorta, bicuspid aortic valve, renal anomalies, infertility, hypothyroidism, osteoporosis
- What are the key clinical features of Down syndrome (Trisomy 21)?
Features: Hypotonia, flat face, epicanthic folds, upslanting palpebral fissures, single palmar crease, sandal gap toe, intellectual disability
- What are the genetic and clinical features of Turner syndrome?
Turner: 45,X (or mosaicism), short stature, webbed neck, shield chest, lymphedema, primary amenorrhea
- What are the key features of Patau syndrome (Trisomy 13)?
Trisomy 13: Cleft lip/palate, holoprosencephaly, polydactyly, microphthalmia, severe ID
- Karyotype: 47,XX/XY+13
- What are the common medical complications associated with Down syndrome?
Complications: Congenital heart defects (AVSD), hypothyroidism, leukemia risk, hearing loss, GI anomalies (duodenal atresia), atlantoaxial instability
- What is the genetic cause and presentation of Fanconi anemia?
Fanconi anemia: AR/X-linked (DNA repair defects)
- Pancytopenia, short stature, radial anomalies, café-au-lait spots, leukemia risk
- What are the features of Bloom syndrome?
Bloom syndrome: AR, BLM gene (DNA helicase defect)
- Growth retardation, sun-sensitive rash, immunodeficiency, cancer predisposition
- What are the features and genetic defect in Ataxia-telangiectasia?
Ataxia-telangiectasia: AR (ATM gene)
- Cerebellar ataxia, oculocutaneous telangiectasia, recurrent infections, cancer risk
- What is the genetic basis and presentation of Beckwith-Wiedemann syndrome?
Beckwith-Wiedemann: Imprinting disorder (11p15, IGF2/H19)
- Macrosomia, macroglossia, organomegaly, omphalocele, Wilms tumor risk
- What are the types and clinical signs of osteogenesis imperfecta?
OI: COL1A1/2 gene mutation
- Features: Blue sclerae, fractures, hearing loss, dental issues
- Types I–IV, type II lethal
- What are the red flag signs that suggest a genetic syndrome in a pediatric patient?
Red flags: Multiple congenital anomalies, dysmorphic features, developmental delay, growth failure, consanguinity, family history
- What is the genetic basis and presentation of congenital adrenal hyperplasia (CAH)?
CAH: AR (most common 21-hydroxylase deficiency, CYP21A2 gene)
- Salt-wasting crisis, virilization, ambiguous genitalia in females
- What are the types of CAH and how are they diagnosed genetically?
Types: Classic salt-wasting, simple virilizing, non-classic
- Diagnosed by elevated 17-OH progesterone and genetic testing
- What are the features and diagnosis of Silver-Russell syndrome?
Silver-Russell: Hypomethylation of 11p15 or maternal UPD7
- Features: IUGR, triangular face, limb asymmetry, feeding difficulty
- What are the genetic and clinical features of Fragile X syndrome?
Fragile X: X-linked, CGG repeat on FMR1 gene
- Features: Macroorchidism, long face, large ears, autism, ID, hand-flapping
- What are the features and genetics of Alagille syndrome?
Alagille: AD (JAG1/NOTCH2 gene)
- Features: Cholestasis, butterfly vertebrae, posterior embryotoxon, cardiac defects, facial features
- What are the inheritance patterns and features of mitochondrial disorders?
Mitochondrial disorders: Maternal inheritance
- Affect high-energy tissues (muscle, brain), variable penetrance and severity
- What is genetic counseling and what are its main principles?
Genetic counseling: Process of advising patients on inherited conditions, recurrence risks, testing options, family planning
- What is the presentation and inheritance pattern of Marfan syndrome?
Marfan: AD (FBN1 gene mutation)
- Features: Tall, long limbs, lens dislocation, aortic dilation, scoliosis
- What are the common modes of inheritance in pediatric genetic disorders?
Modes: Autosomal dominant, autosomal recessive, X-linked recessive, X-linked dominant, mitochondrial, multifactorial
- What is the difference between genetic mosaicism and chimerism?
Mosaicism: Two cell lines from one zygote (postzygotic mutation)
- Chimerism: Two genetically distinct zygotes (e.g., twin fusion)