Order Code CASRG CASR Full Gene Sequencing with Deletion/Duplication, Varies

Ordering Guidance

Targeted testing for familial variants (also called site-specific or known mutations testing) is available for the genes on this panel. See FMTT / Familial Variant, Targeted Testing, Varies. To obtain more information about this testing option, call 800-533-1710.

Testing for the CASR gene as part of a customized panel is available. For more information, see CGPH / Custom Gene Panel, Hereditary, Next-Generation Sequencing, Varies.

Shipping Instructions

Specimen preferred to arrive within 96 hours of collection.

Specimen Required

Patient Preparation: A previous bone marrow transplant from an allogenic donor will interfere with testing. Call 800-533-1710 for instructions for testing patients who have received a bone marrow transplant.

Container/Tube:

Preferred: Lavender top (EDTA) or yellow top (ACD)

Acceptable: Any anticoagulant

Specimen Volume: 3 mL

Collection Instructions:

1. Invert several times to mix blood.

2. Send whole blood specimen in original tube. Do not aliquot.

Specimen Stability Information: Ambient (preferred)/Refrigerated

Forms

1. New York Clients-Informed consent is required. Document on the request form or electronic order that a copy is on file. The following documents are available:

-Informed Consent for Genetic Testing (T576)

-Informed Consent for Genetic Testing (Spanish) (T826)

2. Hereditary Renal Genetic Testing Patient Information (T918)

3. If not ordering electronically, complete, print, and send a Renal Diagnostics Test Request (T830) with the specimen.

Useful For

Providing a genetic evaluation of individuals with a personal or family history of familial hypocalciuric hypercalcemia, neonatal severe primary hyperparathyroidism, or autosomal dominant hypoparathyroidism (autosomal dominant hypocalcemia)

Establishing a diagnosis of familial hypocalciuric hypercalcemia, neonatal severe primary hyperparathyroidism, or autosomal dominant hypoparathyroidism (autosomal dominant hypocalcemia)

As a part of the workup for patients with primary hyperparathyroidism, idiopathic hypoparathyroidism, and Bartter syndrome

Genetics Test Information

This test utilizes next-generation sequencing to detect single nucleotide, deletion-insertion, and copy number variants in the CASR gene, which is associated with autosomal dominant familial hypocalciuric hypercalcemia, autosomal dominant and autosomal recessive neonatal severe primary hyperparathyroidism, autosomal dominant hypocalcemia (hypoparathyroidism), and autosomal dominant hypocalcemia with Bartter syndrome. See Method Description for additional details.

Identification of a disease-causing variant may assist with diagnosis, prognosis, clinical management, familial screening, and genetic counseling for autosomal dominant familial hypocalciuric hypercalcemia, autosomal dominant and autosomal recessive neonatal severe primary hyperparathyroidism, autosomal dominant hypoparathyroidism (also known as autosomal dominant hypocalcemia), and autosomal dominant hypoparathyroidism with features of Bartter syndrome.

Special Instructions

Method Name

Sequence Capture and Next-Generation Sequencing (NGS)

Reporting Name

CASR Full Gene Analysis

Specimen Type

Varies

Specimen Minimum Volume

1 mL

Specimen Stability Information

Specimen Type	Temperature	Time	Special Container
Varies	Varies

Reject Due To

All specimens will be evaluated at Mayo Clinic Laboratories for test suitability.

Reference Values

An interpretive report will be provided.

Method Description

Next-generation sequencing (NGS) and/or Sanger sequencing is performed to test for the presence of variants in coding regions and intron/exon boundaries of the CASR gene, as well as some other regions that have known disease-causing variants. The human genome reference GRCh37/hg19 build was used for sequence read alignment. At least 99% of the bases are covered at a read depth over 30X. Sensitivity is estimated at above 99% for single nucleotide variants, above 94% for deletions-insertions (delins) less than 40 base pairs (bp), above 95% for deletions up to 75 bp and insertions up to 47 bp. NGS and/or a polymerase chain reaction-based quantitative method is performed to test for the presence of deletions and duplications in the CASR gene.

There may be regions of the CASR gene that cannot be effectively evaluated by sequencing or deletion and duplication analysis as a result of technical limitations of the assay, including regions of homology, high guanine-cytosine (GC) content, and repetitive sequences.(Unpublished Mayo method)

The reference transcript for CASR gene is NM_000388.4. Reference transcript numbers may be updated due to transcript reversioning. Always refer to the final patient report for gene transcript information referenced at the time of testing. Confirmation of select reportable variants may be performed by alternate methodologies based on internal laboratory criteria.

Day(s) Performed