CHD7 Gene Analysis Full Gene Sequence
Label Mnemonic: CHD7
Epic Lab Code: LAB4836
Downtime Form: A-1a Miscellaneous Request
Commercial Mail-out Laboratory
5231 RCP
356-8593
Specimen(s):
Whole Blood
Collection Medium:
Lavender top tube 3 mL (EDTA)
Minimum:
2-5 mL whole blood (EDTA)
Delivery Instructions:
Submit specimen to laboratory as soon as possible after collection.
Turn Around Time:
9-10 weeks upon receipt at reference laboratory
Reference Range:
Capillary Sequencing
Comments:
This mailout test requires pathologist approval for orders during inpatient encounters. Mailouts staff will not process order without approval. The pathologist covering mailouts approval can be reached at pager #5379. If approval is given, the name of the pathologist can be selected in the drop-down menu to the right of the approval warning in Epic when ordering the test.

Clinical features: CHARGE syndrome refers to a specific set of birth defects, including coloboma of the eye, heart defects, choanal atresia, mental and growth retardation and ear anomalies or hearing loss. Congenital anomalies, which when seen together are quite specific to CHARGE syndrome, include coloboma of the iris, retina, choroid and/or optic disc with or without microphthalmos; choanal atresia or stenosis; and hypoplastic semi-circular canals. Cranial nerve dysfunction is a minor sign and include anosmia, neurosensory deafness, facial palsy and swallowing difficulties. Ear abnormalities involving the helices, middle ear and inner ear are very common and were seen in 90% of affected individuals in one study (Stromland, 2005). Affected patients may also have genital abnormalities (hypogonadotropic hypogonadism), pre- and post-natal growth deficiency, hypotonia, and characteristic hands (broad palms with "hockey-stick" palmar crease, short fingers and small/unusual thumbs). The characteristic facial appearance includes square face with broad prominent forehead, arched eyebrows, large eyes with or without ptosis, prominent nasal bridge and columella, flat midface, small mouth and facial asymmetry. CHARGE syndrome encompasses additional nonspecific features such as mental retardation, skeletal abnormalities, hypodontia, orofacial clefting, tracheoesophageal fistula, and urinary tract and renal anomalies.

Reasons for referral:
1. Confirmation of the clinical diagnosis
2. Differential diagnosis from the 22q11 deletion spectrum
   (VCFS/DiGeorge syndrome), VACTERAL association, PAX2 mutations and
   Retinoic embryopathy
3. Development of appropriate evaluation and management plan
4. Genetic counseling
5. Prenatal diagnosis in at-risk pregnancies

Please print, complete and submit the following forms to the lab, with the specimen and the A-1a Miscellaneous Request: Informed Consent for DNA Testing and the Sample Submission Form - Testing Services for Rare Mendelian Disorders from GeneDx DNA Diagnostic Experts.
Methodology:
See report
CPT Code:
81407