Neurodevelopmental disorders (NDDs) affect more than 4.6 million Americans and there is a growing body of evidence that shows strong support for the role of genetics in NDDs. To better serve the needs of clinicians and patients, we offer a range of diagnostic testing options for NDDs.
NDDs are disabilities associated primarily with the functioning of the brain and neurological system. Individuals often present with global developmental delays (GDD), intellectual disabilities (ID) and/or characteristics of autism spectrum disorders (ASD). Epilepsy can also be common.
2-3% of Americans are diagnosed with intellectual disability (ID).1 ID is defined as:2
ID is a developmental consequence that can be syndromic (occurring with other congenital anomalies or medical problems) or non-syndromic (isolated). Causes include complex inherited conditions resulting from chromosome or single gene changes/errors during embryogenesis, prenatal and perinatal complications, and inborn errors of metabolism. ID can result from mutations in genes that are inherited in a variety of patterns, including autosomal dominant, autosomal recessive, and X-linked.
Genetic testing can identify the underlying cause for approximately 1 in every 5 affected individuals,3 and is recommended for all children with ID by the American College of Medical Genetics and Genomics (ACMG), the American Academy of Neurology (AAN) and the American Academy of Pediatrics (AAP). 3,4,5 The following testing strategy incorporates these guidelines and could be considered in the absence of other indications:
Autism Spectrum Disorders
1-2% of American children are found to have an autism spectrum disorder (ASD).6 ASDs are a group of NDDs that can cause significant behavioral, social and communication difficulties that begin in early childhood ASDs encompass autism, Asperger syndrome, and pervasive developmental delay-not otherwise specified (PDD-NOS).
In some individuals, the ASD is caused by an inherited condition, such as fragile X syndrome, Rett syndrome, or tuberous sclerosis complex. Confirmation of a genetic cause helps guide medical management and recommendations for an individual/family, as well as tailor genetic counseling and recurrence risk estimates.
Genetic testing can confirm the underlying cause for 30-40% of affected individuals, 7 and is recommended by the American College of Medical Genetics and Genomics (ACMG), the American Academy of Neurology (AAN) and the American Academy of Pediatrics (AAP). 3,4,5 The following testing strategy incorporates these guidelines and could be considered in the absence of other indications.
Our Neurodevelopmental Testing Includes:
|Test Name||Turnaround Time|
|SNP Array||2-3 weeks|
|Fragile X-associated disorders||1-2 weeks|
(140 gene panel for syndromic and non-syndromic ID)
(16 genes, ACMG-recognized syndromes)
(48 genes, syndromic and non-syndromic autism)
(22 genes for Rett, Angelman and related disorders)
(196 gene panel for ID, ASD and epilepsy)
(MECP2 gene sequencing and deletion/duplication)
(methylation studies with reflex to UBE3A gene sequencing
|PTEN-related disorders||1-3 weeks|
|Tuberous sclerosis complex||2-4 weeks|
(5 gene panel for Cornelia de Lange syndrome)
|Rubinstein-Taybi syndrome||2-4 weeks|
|Coffin-Lowry syndrome||2-4 weeks|
|Smith-Magenis syndrome||2-4 weeks|
|Sotos syndrome||2-4 weeks|
(rapid option is 2-5 weeks)