Table III.
Testing approach.
| Genetic testing offered prenatally | |
|---|---|
| Microarraya only | 34 (28%) |
| Karyotype only | 23 (19%) |
| Karyotype and microarraya,b | 14 (12%) |
| No testing offered | 12 (10%) |
| No response or is not involved in prenatal care | 12 (10%) |
| Karyotype and/or microarray and Fanconi anemia testing | 8 (7%) |
| Karyotype and deletion 22q11.2 testingc | 7 (6%) |
| Karyotype and/or microarray and specific gene testingd | 4 (3%) |
| Karyotype and/or microarray and Fanconi anemia testing and specific gene testingd | 3 (2%) |
| Karyotype and deletion 22q11.2 testing and Fanconi anemia testing | 2 (2%) |
| Specific gene testingd only | 1 (1%) |
| Fanconi anemia testing only | 1 (1%) |
|
| |
| Genetic testing offered postnatally | |
| Microarray onlye | 53 (44%) |
| Karotype and/or microarray and Fanconi anemia testingf | 29 (24%) |
| Karyotype and microarray | 13 (11%) |
| No testing | 9 (7%) |
| Microarray and single gene testingd | 3 (2%) |
| Microarrray and Fanconi anemia testing and single gene testingd | 3 (2%) |
| Research enrollment only | 2 (2%) |
| Karyotype and microarray and single gene testingd | 1 (1%) |
| Karyotype and deletion 22q11.2 testing | 1 (1%) |
| Fanconi anemia testing and single gene testingd | 1 (1%) |
| Karyotype and microarray and research testing | 1 (1%) |
| Microarray and Fanconi anemia testinge and mitochondrial testingg | 1 (1%) |
|
| |
| Would the presence of dysmorphic facial features alter the diagnostic impression? | |
| Yes | 95 (79%) |
| No | 26 (21%) |
|
| |
| Would unexplained neurocognitive impairment alter the diagnostic impression? | |
| Yes | 97 (80%) |
| No | 24 (20%) |
Some respondents additionally indicated the type of array they would use, such as “high-density SNP array”, though most simply indicated the choice of performing a microarray.
One respondent additionally ascertaining family history of breast cancer.
Of these, three mentioned deletion 22q11.2 testing only in the context of cardiac malformations.
Genes mentioned as examples include SALL1, SALL4, and PTEN (the latter in the context of hydrocephalus).
Several respondents mentioned an array would only be done in the case of cognitive delay, but since this can be hard to ascertain in an infant or young child, they would tend to request a microarray in any infant/young child.
Several respondents mentioned Fanconi anemia testing only in the presence of limb abnormalities.
Mitochondrial testing would be done only in the context of clinical signs such as hypotonia.