Mental retardation may occur as a consequence of a chromosomal abnormality. In some patients the retardation is associated with a submicroscopic, subtelomeric rearrangement. De Vries et al developed a checklist to help identify patients who should be tested for a subtelomeric rearrangement.
Parameters:
(1) family history of mental retardation
(2) prenatal onset of growth retardation
(3) postnatal growth abnormalities (stature, head circumference)
(4) facial dysmorphic features (hypertelorism, nasal anomalies, ear anomalies)
(5) non-facial dysmorphism and congenital abnormalities
|
Parameter |
Finding |
Points |
|
family history of mental retardation |
none |
0 |
|
|
compatible with Mendelian inheritance |
1 |
|
|
incompatible with Mendelian inheritance |
2 |
|
prenatal onset of growth retardation |
absent |
0 |
|
|
present |
2 |
|
postnatal growth abnormalities |
none |
0 |
|
|
1 point for each up to maximum of 2 points: microcephaly, macrocephaly, short stature, tall stature |
1-2 |
|
facial dysmorphic features |
0 or 1 |
0 |
|
|
>= 2 |
2 |
|
nonfacial dysmorphism and congenital abnormalities |
none |
0 |
|
|
1 points for each up to a maximum of 2 points: hand anomalies, heart anomaly, hypospadias with/without undescended testis |
1 - 2 |
total score =
= SUM(points for all 5 parameters)
Interpretation:
• minimum score: 0
• maximum score: 10
• Subtelometric testing is warranted for a child with a score >= 3.
|
Cutoff Score |
Sensitivity |
Specificity |
|
>= 3 |
100% |
27% |
|
>= 4 |
89% |
43% |
|
>= 5 |
70% |
69% |
|
>= 6 |
56% |
88% |
|
>= 7 |
33% |
94% |
|
>= 8 |
19% |
95% |
|
>= 9 |
11% |
99% |
from Table 3, page 148 (De Vries et al)
NOTE: Baralie (2001) states that the maximum score is 11, but the first parameter can only give 0, 1 or 2 points.
Specialty: Genetics, Neurology
ICD-10: ,
