BACKGROUND Multiple lines of evidence indicate a strong genetic contribution to autism spectrum disorders (ASDs). Current guidelines for clinical genetic testing recommend a G-banded karyotype to detect chromosomal abnormalities and fragile X DNA testing, but guidelines for chromosomal microarray analysis have not been established. PATIENTS AND METHODS A cohort of 933 patients received clinical genetic testing for a diagnosis of ASD between January 2006 and December 2008. Clinical genetic testing included G-banded karyotype, fragile X testing, and chromosomal microarray (CMA) to test for submicroscopic genomic deletions and duplications. Diagnostic yield of clinically significant genetic changes was compared. RESULTS Karyotype yielded abnormal results in 19 of 852 patients (2.23% [95% confidence interval (CI): 1.73%–2.73%]), fragile X testing was abnormal in 4 of 861 (0.46% [95% CI: 0.36%–0.56%]), and CMA identified deletions or duplications in 154 of 848 patients (18.2% [95% CI: 14.76%–21.64%]). CMA results for 59 of 848 patients (7.0% [95% CI: 5.5%–8.5%]) were considered abnormal, which includes variants associated with known genomic disorders or variants of possible significance. CMA results were normal in 10 of 852 patients (1.2%) with abnormal karyotype due to balanced rearrangements or unidentified marker chromosome. CMA with whole-genome coverage and CMA with targeted genomic regions detected clinically relevant copy-number changesin7.3%(51 of 697) and 5.3%(8 of 151) of patients, respectively, both higher than karyotype. With the exception of recurrent deletion and duplication of chromosome 16p11.2 and 15q13.2q13.3, most copy-number changes were unique or identified in only a small subset of patients. CONCLUSIONS CMA had the highest detection rate among clinically available genetic tests for patients with ASD. Interpretation of microarray data is complicated by the presence of both novel and recurrent copy-number variants of unknown significance. Despite these limitations, CMA should be considered as part of the initial diagnostic evaluation of patients with ASD.

The goal of this practice resource is to provide genetic counselors and other healthcare professionals with a resource to reference when providing genetic counseling services to individuals and families undergoing evaluation for neurofibromatosis (NF) or who have received a diagnosis of NF, including neurofibromatosis type 1 (NF1), neurofibromatosis type 2 (NF2), and schwannomatosis (SWN). Currently, there is no known standard approach to genetic counseling in NF. This resource may be useful in a number of different healthcare settings. 1.1.1 | Pediatric or adult genetic counseling session (general genetics or specialty clinic) These sessions may occur in conjunction with a diagnosing provider, such as a physician or nurse practitioner. • Diagnostic evaluation based on clinical features and/or family history.

In January 2007 the American Medical Association added a new Current Procedural Terminology(R) (CPT) code, 96040, for "Medical Genetics and Genetic Counseling Services." In order to identify the impact of having this new code and to identify issues with implementation of the code, the National Society of Genetic Counselors (NSGC) CPT(R) Working Group surveyed NSGC members using an internet-based survey tool. The majority of respondents (94%) reported being aware of the new code and over half of the respondents (69%) said they were billing for genetic counseling. Approximately 24% of those billing reported using 96040. Many facilities are not using this code and the reported success of billing using 96040 is highly varied. Continued education may be beneficial to encourage reimbursement for 96040 and follow up is needed to assess the ongoing implementation and impact of the new CPT(R) code.

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