Genetic testing in paediatric patients is used in the investigation of a range of clinical concerns. These may be syndromic features, such as developmental delay, mental retardation, autistic spectrum disorders, neurodevelopmental disorders, short stature and delayed puberty, or they may be more specific, such as in diagnosis of suspected cystic fibrosis. In neonatology genetic testing may often be used for the investigation of dysmorphic features, hypotonia, ambiguous genitalia and other clinical features associated with known genetic diseases. Genomic Diagnostics offers a range of genetic testing for the diagnosis of syndromic or suspected genetic disorders in children. These methods detect changes in the chromosomes of a child.
Chromosomal microarray (molecular chromosome studies) is a genomic test which detects gains or losses of chromosomal material at a high resolution. It is the best practice first line test in the investigation of patients with intellectual disability, congenital anomalies, autism spectrum disorder or developmental delay, along with other more specific tests, such as Fragile X testing.
Conventional karyotype is the genetic test used for the investigation of balanced chromosomal disorders where there is no loss or gain of chromosomal material, or if the clinical presentation suggestive of low grade mosaicism such as Turner syndrome. FISH is a molecular cytogenetic test, frequently used as a rapid test for specific genes or chromosome regions associated with known clinical syndromes (such as Cri Du Chat Syndrome).