Recurrence risk:
Risk factor - increasing maternal age
- <35 years: RR = age-related risk +1%
- >35 years: RR = age-related risk
The overall recurrence risk for having a live-born child who has any trisomy is ~1% added to the mother’s age-related risk for having a child who has a trisomy, which increases over time.
Recurrence risk:
Risk factor - increasing maternal age
- <35 years: RR = age-related risk +1%
- >35 years: RR = age-related risk
The overall recurrence risk for having a live-born child who has any trisomy is ~1% added to the mother’s age-related risk for having a child who has a trisomy, which increases over time.
Germline mosaicism needs to be considered when an apparently new _____ trait develops.
Germline mosaicism needs to be considered when an apparently new AD trait develops.
A mother carrying a mitochondrial DNA (mtDNA) mutation passes it on to all her offspring whereas the father carrying the mutation passes it to none of his offspring
A mother carrying a mitochondrial DNA (mtDNA) mutation passes it on to all her offspring whereas the father carrying the mutation passes it to none of his offspring
Same risk as having no known relatives = Only 1 2nd-degree relative affected
- Do not require counseling
Moderate risk = 1 1st-degree relative with disease onset at average age or 2 affected 2nd-degree relatives on the same side of the family
- Only need counseling in unusual circumstances
High risk - should be sent for counseling
Same risk as having no known relatives = Only 1 2nd-degree relative affected
- Do not require counseling
Moderate risk = 1 1st-degree relative with disease onset at average age or 2 affected 2nd-degree relatives on the same side of the family
- Only need counseling in unusual circumstances
High risk - should be sent for counseling
AAP has advised against the predictive genetic testing of children for adult-onset genetic disorders until the child reaches adulthood at least 18yo
AAP has advised against the predictive genetic testing of children for adult-onset genetic disorders until the child reaches adulthood at least 18yo
TRISOMY 21 DOWNS
TRISOMY 21 DOWNS
Trisomy 21
Classic signs
- Hands and feet:
- Hands are short and broad with single transverse palmar crease (as 10% of the general population does)
- Sandal toe (wide gap between 1st and 2nd toes), brachydactyly (short broad fingers and toes)
- 5th finger middle phalanx hypoplasia/clinodactyly
Trisomy 21
Classic signs
- Hands and feet:
- Hands are short and broad with single transverse palmar crease (as 10% of the general population does)
- Sandal toe (wide gap between 1st and 2nd toes), brachydactyly (short broad fingers and toes)
- 5th finger middle phalanx hypoplasia/clinodactyly
Trisomy 21
Diagnosis
- ____ analysis may be used as fast diagnostic tool, but it must be followed by ____ for etiologic diagnosis and recurrence risk.
- Nondisjunction: Karyotype shows 47 chromosomes instead of usual 46 chromosomes.
- Robertsonian translocation: If karyotyping reveals an unbalanced translocation as the reason, then cytogenetic analysis or karyotypes of both parents is recommended to determine which (if either) parent contributed the chromosome in order to provide proper genetic counseling and determine recurrence risk.
Management
Trisomy 21
Diagnosis
- Rapid fluorescence in situ hybridization FISH analysis may be used as fast diagnostic tool, but it must be followed by karyotyping for etiologic diagnosis and recurrence risk.
- Nondisjunction: Karyotype shows 47 chromosomes instead of usual 46 chromosomes.
- Robertsonian translocation: If karyotyping reveals an unbalanced translocation as the reason, then cytogenetic analysis or karyotypes of both parents is recommended to determine which (if either) parent contributed the chromosome in order to provide proper genetic counseling and determine recurrence risk.
Management
TRISOMY 18 EDWARDS
- 2nd most common autosomal trisomy.
TRISOMY 18 EDWARDS
- 2nd most common autosomal trisomy.
TRISOMY 13 PATAU
TRISOMY 13 PATAU
Klinefelter syndrome (47, XXY karyotype)
Klinefelter syndrome (47, XXY karyotype)
47,XXX Syndrome / Triple X Syndrome
47,XXX Syndrome / Triple X Syndrome
47, XYY Male
47, XYY Male
Turner syndrome
- 45X
Turner syndrome
- 45X
Turners
Noonan
Turners
Noonan
4p Deletion (_____ Syndrome)
4p Deletion (Wolf-Hirschhorn Syndrome)
5p Deletion (_____ Syndrome)
5p Deletion (Cri-Du-Chat Syndrome)
18q Deletion (_____ Syndrome)
18q Deletion (de Grouchy Syndrome)
_____ Deletion: Prader-Willi Syndrome
15q11-13 Deletion: Prader-Willi Syndrome
15q11-13 Deletion: Angelman Syndrome
15q11-13 Deletion: Angelman Syndrome
____ Deletion Williams Syndrome
7q11. 23 Deletion Williams Syndrome
- Defect in elastin (ELN)
- Pt:
- “Elfin” facies: Broad forehead, bitemporal narrowing, hypertelorism, medial eyebrow flare, large earlobes, shortened upturned nose with flattened nasal bridge, elongated philtrum with prominent down-turned lower lip, wide mouth, small jaw, underdeveloped teeth
- Gregarious personality “cocktail personality” “loquacious”
- Stellate pattern of the iris
- Most common cardiovascular problem seen in Williams is supravalvular aortic stenosis (present in 75%).
- Intellectual disability
- Hypercalcemia
____ Deletion WAGR Syndrome
11p13 Deletion WAGR Syndrome
\_\_\_\_ Deletion (Velocardiofacial syndrome, DiGeorge syndrome, Shprintzen syndrome, conotruncal anomaly face syndrome) - Path: Developmental defect of derivatives of the \_\_\_\_\_\_\_ pouches, resulting in agenesis or hypoplasia of the \_\_\_\_ and \_\_\_\_ gland, conotruncal heart defects, and branchial arch defects
22q11. 2 Deletion (Velocardiofacial syndrome, DiGeorge syndrome, Shprintzen syndrome, conotruncal anomaly face syndrome)
- Path: Developmental defect of derivatives of the 3rd and 4th pharyngeal pouches, resulting in agenesis or hypoplasia of the thymus and parathyroid gland, conotruncal heart defects, and branchial arch defects
Pierre Robin Sequence
- Path: Embryologic defect of ___________. This leads to a displacement of the tongue, which in turn interrupts the closure of the lateral palatine ridges and results in a U-shaped cleft palate.
Pierre Robin Sequence
- Path: Embryologic defect of mandibular hypoplasia. This leads to a displacement of the tongue, which in turn interrupts the closure of the lateral palatine ridges and results in a U-shaped cleft palate.