ATTN: <Medical Director/ Physician Name>, M.D.
<Insurance ID Number>
<Enter Group #>
Dear Medical Director:
I am writing this letter on behalf of my patient <patient name> to request coverage for chromosomal microarray testing to determine the genetic etiology of <Select one: developmental delay, intellectual disability, autism spectrum disorder, multiple congenital anomalies>. This letter documents the medical necessity for chromosomal microarray testing and as such provides information about the patient’s medical history.
Results from the test will be used to guide appropriate medical care for the patient.
I have determined that this test is medically necessary because of the following aspects of this patient’s history:
<Patient Name> is a <age in months or years as appropriate> <boy or girl> with a suspected diagnosis of <Select one: developmental delay, intellectual disability, autism spectrum disorder, multiple congenital anomalies> due to the following clinical findings:
1. <Symptom #1 with ICD-9 code>
2. <Symptom #2 with ICD-9 code>
3. <Symptom #3 with ICD-9 code>
<Add additional details, such as results of previous testing if any>
Taken together, these findings suggest that the patient may have a disorder that involves one or more genes and could be caused by chromosomal copy number variants (CNVs).
Rationale for Testing
<Select one: Developmental delay, Intellectual disability, Autism spectrum disorders,
Multiple congenital anomalies> may be caused by environmental factors, genetic factors, or a combination of both. Determining the cause is important for patient management and genetic counseling. Developmental delay, intellectual disability, autism spectrum
disorders (ASDs), and multiple congenital anomalies can be caused by chromosomal abnormalities such as CNVs.
Chromosomal microarray (CMA) testing is a powerful method of identifying these CNVs,
providing much greater resolution than conventional cytogenetics or FISH. Among patients with developmental delay/intellectual disability, ASDs, or multiple congenital anomalies, CMA exhibited a clinical sensitivity of 15% to 20% compared to ~3% for G-banded karyotyping and ~6% for subtelomeric FISH combined with karyotyping.
CMA testing provides benefits to patients, which may include providing a definitive genetic diagnosis, identifying special needs, predicting prognosis, assessing medical risk, and selecting appropriate therapeutic interventions.
Given its clinical sensitivity and clinical relevance, CMA has been recommended as a first-line genetic test for individuals with suspected nonsyndromic developmental delay or intellectual disability, ASDs, or multiple congenital anomalies when not specific to a well-defined syndrome.
I am requesting that <patient name> be approved for the Chromosomal Microarray,
Oligo-SNP test (test code 16478; CPT code 81229) offered by
Quest Diagnostics. This CMA contains over 2.6 million probes and covers regions of known and likely CNVs, providing extensive information across the genome. Quest
Diagnostics genetic counselors are available to assist me in interpreting the results.
In summary, the genetic information provided by this test may help me more accurately diagnose the cause of<Select one: Developmental delay, Intellectual disability, ASD,
Multiple congenital anomalies> and direct treatment accordingly. I hope you will support this letter of medical necessity for <patient name>. Please feel free to contact me at
<phone number> if you have additional questions.
<Physician Name>, MD
NPI #: <Physician NPI#>
Contact Phone No.: <phone number>
1. Shaffer LG, American College of Medical Genetics Professional Practice and Guidelines
Committee. American College of Medical Genetics guideline on the cytogenetic evaluation of the individual with developmental delay or mental retardation.
2. Schaefer GB, Mendelsohn NJ, Professional Practice and Guidelines Committee. Clinical genetics evaluation in identifying the etiology of autism spectrum disorders: 2013 guideline revisions.
3. Ellison JW, Ravnan JB, Rosenfeld JA, et al. Clinical utility of chromosomal microarray analysis.
4. Manning M, Hudgins L, Professional Practice and Guidelines Committee. Array-based technology and recommendations for utilization in medical genetics practice for detection of chromosomal abnormalities.
5. Miller DT, Adam MP, Aradhya S, et al. Consensus statement: Chromosomal microarray is a firsttier clinical diagnostic test for individuals with developmental disabilities or congenital anomalies.
Am J Hum Genet.