Embryo pt.5

Question 1

Incidence of down syndrome

Answer 1

1 in 800

Question 2

Incidence of trisomy 18

Answer 2

1 in 8000

Question 3

Incidence of trisomy 13

Answer 3

1 in 12000

Question 4

Usual clinical manifestations of down syndrome

Answer 4

• Mental deficiency
• brachycephaly
• Flat nasal bridge
• Flattened nose and face
• Protruding tongue
• Upward slant to palpebral fissures
• Transverse palmar flexion crease
• Clinodactyly of the fight finger (curvature of pinky fingure)
• Congenital heart defects
• GI tract abnormalities

Question 5

What is brachycephaly?

Answer 5

• decrease in the anteroposterior dimension of the skull
• Lower than normal ratio of the skull’s length to its width

Question 6

Usual clinical manifestations of Edwards syndrome

Answer 6

• Mental deficiency
• Growth retardation
• Ventricular septal defect
• Hypoplastic nails
• Short sternum
• Prominent occiput (back part of skull)
• Micrognathia (smaller lower jaw)
• Low set malformed eats

Question 7

Usual clinical manifestations of patau syndrome

Answer 7

• Mental deficiency
• Severe CNS malformations
• Sloping forehead
• Malformed ears
• Sloping forehead
• Scalp defects
• Microphthalmia (Eyes are abnormally small and have anatomic malformations
• Polydactyly
• Bilateral cleft lip and/or palate

Question 8

Incidence of triple x syndrome

Answer 8

1 in 1000

Question 9

Incidence of 47 XXY

Answer 9

1 in 1000

Question 10

Incidence of 47 XYY

Answer 10

1 in 1000

Question 11

Triple X syndrome usual characteristics

Answer 11

• Normal in appearance
• Usually fertile
• 15-25% are mildly mentally deficient

Question 12

Klinefelter syndrome characteristics

Answer 12

• Small testes
• Hyalinization of seminiferous tubules
• Aspermatogenesis
• Around 40% have gynecomastia
• Often tall with disproportionately long lower limbs

Question 13

Contiguous syndrome most commonly affected chromosomes

Answer 13

Chromosome 15 q12 (Angelman and Prader Willi), Chromosome 17 (Williams and Miller Deiker, Smith Magenis), Chromosome 22q11 (DiGeorge, Velocardiofacial)

Question 14

47 XYY usual characteristics

Answer 14

• Appear normal
• Usually tall
• Often exhibit aggressive behavior

Question 15

Cause of DiGeorge

Answer 15

Del 22q11 (some cases)

Question 16

Cause of Prader willi

Answer 16

Del 15q 12 (most cases) from paternal origin

Question 17

Cause of Angelman

Answer 17

Del 15q 12 (most cases) from maternal origin

Question 18

Cause of velocardiofacial

Answer 18

Del 22q11 (most cases)

Question 19

Examples of contiguous gene syndromes

Answer 19

• Prader Willi
• Angelman
• Velocardiofacial
• Beckwith-Wiedemann
• Williams
• Smith-Magenis
• Di George
• Miller-Dieker

Question 20

Cause of Miller-Dieker

Answer 20

Del 17 p13.3 (most cases)

Question 21

Cause of Beckwith-Wiedemann

Answer 21

Dup 11 p15(some cases) from paternal

Question 22

Cause of Williams

Answer 22

Del 17 q11.23 (most cases)

Question 23

Cause of Smith Magenis

Answer 23

Del 17 p11.2

Question 24

Clinical features of Prader-Willi

Answer 24

• Hypotonia
• Hypogonadism
• Extreme obesity with hyperphagia
• Distinct face
• Short stature
• Small hands and feet
• Mild developmental delay
• Learning disability

Question 25

Clinical features of Angelman

Answer 25

- Microcephaly - Macrosomia - Ataxia - Excessive laughter - Seizure - Severe mental deficiency

Question 26

Clinical features of Miller Dieker

Answer 26

- Type 1 lissencephaly - Dysmorphic face - Seizures - Severe developmental delay - Cardiac defects

Question 27

What is lissencephaly?

Answer 27

Literally means "smooth brain," is a rare, gene-linked brain malformation characterized by the absence of normal convolutions (folds) in the cerebral cortex)

Question 28

Clinical features of DiGeorge

Answer 28

- Thymic hypoplasia - Parathyroid hypoplasia - Conotruncal cardiac defects - Facial dysmorphism

Question 29

Clinical feature of velocardiofacial

Answer 29

- Palatal defects - Hypoplastic alae nasi - Long node - Conotruncal cardiac defects - Speech delay - Learning disorder - Schizophrenia like disorder

Question 30

Clinical features of Smith-Magenis

Answer 30

- Brachycephaly - Broad nasal bridge - Prominent Jaw - Shot and broad hands - Speech delay - Mental deficiency

Question 31

Clinical features of Williams

Answer 31

- Short stature - Hypercalcemia - Cardiac defects, especially supravalvular aortic stenosis - Characteristic elfin-like face - Mental deficiency

Question 32

Beckwith-Wiedemann clinical features

Answer 32

- Macrosomia - Macroglossia - Omphalocele (some cases) - Hypoglycemia - hemihypertrophy - Transverse ear lobes

Question 33

Macrosomia meaning

Answer 33

Larger than average fetus/baby

Question 34

Macroglossia meaning

Answer 34

Tongue is larger than normal