Cost 
$1,000.00
TAT 
4 weeks
CPT Code 
81404
Test Code 
2131
Test Methods 
Deletion/Duplication analysis
Specimen Types Accepted 
Blood
Saliva
Cultured Cells
Extracted DNA
Notes 
If sending saliva, 2 kits are required.

Males with Allan-Herndon-Dudley syndrome [OMIM #30523], also known as MCT8-specific thyroid hormone cell transporter (THCT) deficiency, MCT8 deficiency, syndromic X-linked mental retardation with high serum T3, and thyroid hormone cell transport defect, have severe developmental delay, gait disturbance, dystonia, and poor head control.  Patients with this condition also have a thyroid hormone defect presenting with unusual combination of increased serum 3,3’,5-triiodothyronine (T3), decreased serum thyroxine (T4) and low 3,3’,5’-triiodothyronine (reverse T3, rT3) concentrations found in both males and to a lesser degree in carrier females.  However, T3 and reverse T3 are not commonly measured and normal ranges for children are not available in routine laboratories.  Mutations of the SLC16A2 (MCT8) [OMIM #300095] gene, or monocarboxylate transporter 8, have been identified in patients with MCT8-specific THCT deficiency.

All samples will undergo thyroid hormone testing in Dr. Refetoff’s Endocrinology Laboratory at the University of Chicago to examine the presence of thyroid hormone abnormalities before SLC16A2 sequencing.  To date, all patients with SLC16A2 abnormalities have demonstrated thyroid hormone abnormalities.

Deletions and/or duplications of the SLC16A2 gene as causative of disease have been reported.

Contact the MCT8 Organization (http://www.mct8organization.org) for more information and support.