Genetic Syndromes
Sex Chromossome Disorders
Fragile X Syndrome
Mild-moderate MR; ADHD and/or autism
Macroorchidism
High-arched palate
Proeminent jaw, forehead and nasal bridge; long, thin face
Most common cause of MR in boys
X-linked; anticipation disorder
Klinefelter
Tx: testosterone in adolescence
behavioural/psychiatric disorders
hypogonadism ==> gynecomastia, lack facial hair
Tall, long limbs, slim, underweight
1:1000; increases with maternal age
47, XXY
Turner Syndrome
Tx:
Estrogen in adolescence
GH for short stature
Cardiac defects
bicuspid aortic valve, CoAo
streak ovaries
mild MR-normal IQ
45,X0
Autossomic
Noonan Syndrome
Delayed puberty
Right-sided CHD ==> pulmonary sternosis
MR in 25%
Phenotype similar to Turner's
Autossomic dominant inheritance with variable expression
Angelman
Uncrontrollable laughter
Severe MR, seizures, tremoulesness
Lack of maternally 15q11
Prader-Willi
Developmental delay
H30
Obesity (obssesive hyperphagia)
Hypogonadism
Hypotonia
Lack of paternal 15q11
DiGeorge Syndrome
CATCH 22
22q11 microdeletion
Hypoparathyroidism
Cognitive impairment
Thymic hypoplasia
Anomalies
Cyanotic CHD
2nd most common genetic diagnosis
Microdeletions of 22q11
Trissomy 13
Severe IUGR, Proound MR
Midline anomalies, cleft lip/palate
Microcephaly (sloping forehead), microphtalmia
1:10.000
Patau Syndrome
Trissomy 18
90% die in 1st year
Profound MR
Cardiac defects ==> 60%
Cleft lip/palate; micrognathia
microcephaly (proeminent occipital), microphtalmia, coloboma of iris
1:6000;
Edwards Syndrome
Trissomy 21
Low IQ / developmental delay
Hypothyroidism
1% risk of leukemia
Cardiac defects ==> 40% AVSD
overall 1:700; rises with maternal age (5% by 45)
Down's Syndrome
