Nance-Horan syndrome, an X-linked condition also known as cataract-dental syndrome, is characterized by ocular manifestations including congenital cataract, microcornea, early-onset nystagmus; ear anomalies; short fourth metacarpal bones; dental anomalies; dysmorphic features; and intellectual disability in males. Most female carriers have eye findings and dental anomalies. Ramprasad et al. (2005) identified mutations in the NHS gene (Xp22.13) in five Nance-Horan syndrome families. The NHS gene has a regulatory role in the development of ocular, craniofacial, and neural tissue.
- Confirmation of a clinical diagnosis of Nance-Horan syndrome in an individual in whom sequence analysis was negative.
- Carrier testing in adults with a family history of Nance-Horan syndrome in whom sequence analysis was negative.
Please note that a "backbone" of probes across the entire genome are included on the array for analytical and quality control purposes. Rarely, off-target copy number variants causative of disease may be identified that may or may not be related to the patient's phenotype. Only known pathogenic off-target copy number variants will be reported. Off-target copy number variants of unknown clinical significance will not be reported.
Submit only 1 of the following specimen types
Preferred specimen type: Whole Blood
Type: Whole Blood
Specimen Requirements:In EDTA (purple top) tube:
Infants (<2 years): 2-3 ml
Children (>2 years): 3-5 ml
Older Children & Adults: 5-10 ml
Specimen Collection and Shipping: Refrigerate until time of shipment. Ship sample within 5 days of collection at room temperature with overnight delivery.
Specimen Requirements:OrageneTM Saliva Collection kit (available through EGL) used according to manufacturer instructions.
Specimen Collection and Shipping: Store sample at room temperature. Ship sample within 5 days of collection at room temperature with overnight delivery.
- Sequence analysis of the NHS gene is available and is required before deletion/duplication analysis.
- Custom diagnostic mutation analysis (KM) is available to family members if mutations are identified by targeted mutation testing or sequencing analysis.
- Prenatal testing is available only for known familial mutations to individuals who are confirmed carriers of mutations. Please contact the laboratory genetic counselor to discuss appropriate testing prior to collecting a prenatal specimen.
- X-Linked Intellectual Disability panels are available for 30, 60, and 90 genes.