Feingold Syndrome
Feingold Syndrome 1
Gene: MYCN
Protein: N-myc proto-oncogene protein
Feingold Syndrome 2
Gene: MIR17HG
Transcript: MIR17-92 cluster (primary transcript for microRNAs MIR17, MIR18, MIR19A, MIR19B, MIR20 and MIR92)
Clinical Characteristics
- Microcephaly
- Short palpebral fissures
- Gastrointestinal atresia
- Digital abnormalities:
- Brachymesophalangy 2 and 5
- Thumb hypoplasia
- 2-3 or 4-5 toe syndactyly
- Normal intelligence or mild to moderate learning disability
- Variable expressivity within and between families
Inheritance pattern: Autosomal dominant
What Can Be Learned From This Test
Testing is performed by sequencing exon 1, coding exons 2 and 3, and the surrounding intronic regions of the MYCN gene. Gene dosage by capillary electrophoresis will be performed (on mutation negative samples) to detect a whole or partial gene deletion, since deletions of the entire MYCN gene have been reported in affected individuals.
Gene deletion testing of the MIR17-92 cluster region will be performed by capillary electrophoresis to determine copy number within the MIR17HG gene.
Sequence analysis of MYCN detects mutations in 65% of individuals with a clinical suspicion of Feingold syndrome. Deletion testing of MYCN detects another 10%. Deletion of MIR17HG accounts for additional cases of Feingold syndrome, but specific detection rate is unknown.
MYCN and MIR17HG are the only genes known to be associated with Feingold syndrome. A negative test for both genes does not rule out a diagnosis of Feingold syndrome, since there may be other genes involved.
Sample Requirements
Draw 2ml–4ml of blood in EDTA/purple-top tube (minimum of 1ml–2ml for infants).
Turnaround time: 10-14 business days per gene
CPT Codes and Cost
Full Gene Sequencing and Dosage MYCN
- Code: 81479
- Cost: $550
Gene Dosage MIR17HG
- Code: 81479
- Cost: $300
Known Variant Testing
- Code: 81479
- Cost: $225