Quality standard
Quality statement 5: Cascade testing
Quality statement 5: Cascade testing
Quality statement
Relatives of people with a confirmed diagnosis of monogenic familial hypercholesterolaemia (FH) are offered DNA testing through a nationwide, systematic cascade process.
Rationale
Most people in the UK with FH are undiagnosed. Cascade testing has been shown to be effective for identifying people with FH, especially when provided nationwide. Nationwide cascade testing ensures that all family members can access DNA testing wherever they live.
Quality measures
The following measures can be used to assess the quality of care or service provision specified in the statement. They are examples of how the statement can be measured, and can be adapted and used flexibly.
Structure
Evidence of local arrangements to ensure that relatives of people with a confirmed diagnosis of monogenic FH are offered DNA testing through a nationwide systematic cascade process.
Data source: Local data collection.
Process
a) Proportion of untested first‑degree relatives of people with a confirmed diagnosis of monogenic FH who are offered cascade testing.
Numerator – The number of people in the denominator offered cascade testing.
Denominator – The number of untested first‑degree relatives of people with a confirmed diagnosis of monogenic FH.
Data source: Local data collection using a dedicated database.
b) Proportion of at‑risk, untested, second‑ and third‑degree relatives of people with a confirmed diagnosis of monogenic FH who are offered cascade testing.
Numerator – The number of people in the denominator offered cascade testing.
Denominator – The number of at‑risk, untested, second‑ and third‑degree relatives of people with a confirmed diagnosis of monogenic FH.
Data source: Local data collection using a dedicated database.
c) Proportion of untested first‑degree relatives of people with a confirmed diagnosis of monogenic FH who receive cascade testing.
Numerator – The number of people in the denominator receiving cascade testing.
Denominator – The number of untested first‑degree relatives of people with a confirmed diagnosis of monogenic FH.
Data source: Local data collection using a dedicated database.
d) Proportion of at‑risk, untested, second‑ and third‑degree relatives of people with a confirmed diagnosis of monogenic FH who receive cascade testing.
Numerator – The number of people in the denominator receiving cascade testing.
Denominator – The number of at‑risk, untested second‑ and third‑degree relatives of people with a confirmed diagnosis of monogenic FH.
Data source: Local data collection using a dedicated database.
What the quality statement means for different audiences
Service providers ensure that systems are in place for relatives of people with a confirmed diagnosis of monogenic FH to be offered DNA testing through a nationwide, systematic cascade process.
Specialists with expertise in FH offer DNA testing to relatives of people with a confirmed diagnosis of monogenic FH through a nationwide, systematic cascade process.
Commissioners ensure that they commission services that offer DNA testing to relatives of people with a confirmed diagnosis of monogenic FH, through a nationwide, systematic cascade process.
Relatives of people with a confirmed diagnosis of FH and a known DNA mutation are offered DNA testing themselves as part of a national scheme.
Source guidance
Familial hypercholesterolaemia: identification and management. NICE guideline CG71 (2008, updated 2019), recommendation 1.2.1
Definitions of terms used in this quality statement
Relatives
At least first‑ and second‑degree biological relatives and third‑degree biological relatives if possible.
[Adapted from NICE's guideline on familial hypercholesterolaemia, terms used in this guideline]
Monogenic FH
Present when an autosomal dominant pattern of inheritance of elevated LDL‑C levels is seen in the extended family of the proband (for example, on average 50% of first‑degree relatives have elevated levels). In relatives, the age‑ and gender‑specific diagnostic cut‑offs in NICE's guideline on familial hypercholesterolaemia should be used because the Simon Broome diagnostic cut‑offs are not appropriate for relatives. The diagnosis of monogenic FH can also be given when the index case carries a documented FH‑causing mutation in the LDLR, APOB or PCSK9 genes.