Pre-testing Requirements
Mutation analysis of the target gene should have been previously performed and a mutation(s) identified (this is often at an overseas/research lab, and may be by an NGS panel/exome sequencing).
Required Mutation Information:
Mutation information must be provided to CHL in advance, in the form of a lab report, or other communication from the laboratory in which the mutation was previously observed.
To clearly identify nuclear gene mutations, please provide:
1.The name of the gene
2.The mutation in cDNA-level notation (e.g. residue c.123 G to T, where c.1 is the A of the initiator ATG)
3.One of the following: (a) the mutation given in protein-level notation, (b) the mutation given in gDNA-level notation, with reference to a specific public reference sequence, (c) a DNA sequence at least 30 bases long with the mutated base and mutation indicated.
4.Mode of inheritance. Autosomal recessive, autosomal dominant, X-linked recessive and X-linked dominant may all be tested using this approach.
Once a mutation is confirmed in an affected individual, carrier testing, and pre-symptomatic testing can be performed on family members at risk for the mutation. For urgent cases, eg. prenatal diagnosis, mutation confirmation in an affected family member can be run concurrently with other samples from the same family.
Reasons for referral:
1.Carrier testing for a specific mutation previously identified in a family
2.Pre-symptomatic testing for a specific mutation previously identified in a family
3.Prenatal diagnosis for a specific nuclear gene mutation previously identified in a family
4.Clinical laboratory confirmation of one or more mutations identified in a research lab
