Clinical case · Familial hypercholesterolaemia

Identifying Familial Hypercholesterolaemia in a Child: A Practical FH Case

A father's premature multivessel coronary disease led to genetic testing of his children. One daughter was found to have familial hypercholesterolaemia and an LDL-C of 5.9 mmol/L. This case works through who else should be tested, who can order the test, when treatment should begin, what LDL-C target to use, and when specialist input is needed.

Dr Reza Moazzeni, MBBS FRACP·Consultant Cardiologist·Heartcare Sydney, Westmead·Last reviewed July 2026

Part 1 — The index case: a parent with familial hypercholesterolaemia

Index case · a man in his late thirties

He presented with severe hypercholesterolaemia: total cholesterol 13 mmol/L, LDL-C 10 mmol/L, untreated. Angiography demonstrated severe triple-vessel disease and he proceeded to coronary artery bypass grafting before the age of 40. Genetic testing identified a pathogenic loss-of-function LDLR variant, confirming heterozygous familial hypercholesterolaemia. His lipoprotein(a) was 162 mg/dL — markedly elevated.

During review he mentioned that he had two daughters. Neither had ever had a cholesterol level checked.

An LDL-C of 10 mmol/L in an adult is not garden-variety hypercholesterolaemia; combined with triple-vessel disease before 40, it is FH until proven otherwise. But the more important point is what that diagnosis obliges us to do next.

Decision point 1

An adult has genetically confirmed FH and two children aged under 18. What is the next most appropriate step?

Wait until the children reach adulthood and test then
Order lipid profiles only
Arrange targeted testing for the known familial variant, and obtain a lipid profile
Arrange coronary calcium scoring in the children

Reveal the answer

Option 3. Where a familial pathogenic variant is known, arrange targeted cascade testing and obtain a lipid profile. The genetic result establishes whether the variant has been inherited; the lipid profile quantifies the phenotype and provides the baseline needed for management. Lipid testing alone can leave diagnostic uncertainty, because LDL-C distributions in affected and unaffected children overlap. Australian guidance supports using genotypic and phenotypic strategies together.

Waiting until adulthood forfeits the years in which treatment does the most good — monogenic FH is usually autosomal dominant with high penetrance, giving each child an independent 50% probability of inheriting the familial variant, and atherosclerosis is already accumulating in childhood. Coronary calcium scoring is not indicated in an asymptomatic child with straightforward heterozygous FH; imaging is reserved for selected specialist circumstances (and clinically indicated homozygous FH) and should not delay treatment.

Who can order the test — the MBS pathway

This is the part most often missed, and it is where the referring clinician can act directly.

Australian practice point

MBS item 73352 — index-case genetic characterisation where no familial variant has yet been identified, provided the item's clinical eligibility criteria are met. These include a Dutch Lipid Clinic Network score of 6 or more, an LDL-C of 6.5 mmol/L or above without an identified secondary cause, or an LDL-C of 5.0–6.5 mmol/L with premature or accelerated atherogenesis. It must be requested by a specialist or consultant physician, and is typically arranged by a lipid clinic or cardiologist.
MBS item 73353 — detection of the known familial variant in a first- or second-degree relative. This can be requested by a GP. The practical requirement is that you hold a copy of the index case's genetic result, which the diagnosing service should provide to the family.

Important — do not re-sequence the child

Cascade testing is targeted single-variant testing, not a repeat gene panel. Ordering a broad FH panel in a relative when the familial variant is already documented is the wrong test, is not what item 73353 covers, and delays the answer. Supply the exact familial variant details on the request form.

Testing the children of a parent with confirmed FH. Index-case characterisation under item 73352 requires a specialist or consultant physician request; targeted cascade testing of relatives under item 73353 does not.

Part 2 — Diagnosing familial hypercholesterolaemia in children

The 14-year-old was asymptomatic and otherwise well, with no tendon xanthomata and a normal examination. Her lipid profile and cascade genetic result:

Test	Result	Interpretation
Total cholesterol	7.4 mmol/L	Markedly elevated
LDL cholesterol	5.9 mmol/L	Severe elevation
HDL cholesterol	1.0 mmol/L	Mildly reduced
Triglycerides	1.2 mmol/L	Not elevated
Non-HDL cholesterol	6.4 mmol/L	Markedly elevated
Targeted familial variant (LDLR)	Detected	Pathogenic loss-of-function LDLR variant — confirms heterozygous FH

Fasting sample. The molecular result is diagnostic here — laboratory reference intervals are population ranges, not paediatric FH criteria, and the Dutch Lipid Clinic Network score should not be used to diagnose FH in children.

Decision point 2

Would you begin lipid-lowering medication now, or continue lifestyle measures alone and reassess?

Reveal the answer

Begin treatment. A prolonged dietary trial is defensible in a milder phenotype, but not here. This adolescent has a documented pathogenic variant, an LDL-C of 5.9 mmol/L, and a first-degree relative who required bypass surgery before 40. Australian guidance recommends considering statin therapy from approximately 8–10 years of age in heterozygous FH, and supports earlier initiation where the family phenotype is adverse. At 14 she is well within the established age range for pharmacotherapy, and treatment should not be delayed further.

Lifestyle measures remain part of care indefinitely — they are adjunctive, not an alternative. The risk of framing them as a trial is that a year passes, the LDL-C is unchanged, and the family concludes that treatment "did not work".

Why age at initiation matters: cumulative LDL burden

The genetic condition is present from conception, and elevated LDL-C exposure begins from birth — so an affected child accumulates decades of excess LDL before an untreated adult would ever reach a lipid clinic. Atherosclerosis is driven by LDL particle concentration multiplied by time. That single concept explains both why her father developed critical disease in his thirties, and why starting her now rather than in her forties changes the trajectory rather than merely improving a number.

Schematic curves of cumulative LDL-C exposure against age, comparing untreated familial hypercholesterolaemia with treatment started in childhood, showing the risk threshold reached decades later when treatment begins early. — Schematic illustration of cumulative LDL-C exposure. Values are conceptual and intended to show the shape of the relationship, not to define an individual threshold.

Evidence · 20-year follow-up

1% vs 26% — treated children versus their affected parents, by age 39. In a 20-year follow-up of children with FH who began statin therapy in childhood, cardiovascular events by age 39 were substantially fewer than in their affected parents at the same age, and carotid intima-media thickness progression was similar to that of unaffected siblings. This was an intergenerational observational comparison rather than a randomised outcomes trial, but the findings strongly support early identification and sustained LDL-C lowering.

Luirink et al., N Engl J Med 2019 — treated children vs affected parents.

Decision point 3

What is the practical LDL-C goal for this 14-year-old?

Below 5.0 mmol/L
Below 3.5 mmol/L, or a reduction of approximately 50% from baseline
Below 1.4 mmol/L, as for adult secondary prevention
No numerical target is needed in children

Reveal the answer

Option 2. For adolescents over 10 years with heterozygous FH, a practical treatment goal is an LDL-C below 3.5 mmol/L or a reduction of at least 50% from baseline. A lower individual target may be considered with specialist input where the family history is particularly adverse or additional major risk modifiers are present.

Conveniently, both measures point the same way here: a 50% reduction from 5.9 mmol/L gives approximately 3.0 mmol/L. Adult secondary-prevention targets are not transferable to a primary-prevention adolescent.

Part 3 — Treating familial hypercholesterolaemia in children

Statin monotherapy first. Begin an age-appropriate statin at a low dose and titrate according to response, tolerability and current Australian product information. Starting the statin alone — rather than combination therapy up front — keeps attribution of any side effects clean and allows adherence to be assessed. Expect roughly a 30–50% LDL-C reduction. Agent choice should be shared between the adolescent, family and treating specialist.
Add ezetimibe 10 mg if target is not reached on a tolerated statin dose, for a further 15–25% reduction. From a baseline of 5.9 mmol/L, combination therapy is a realistic expectation rather than a failure.
Escalate through a specialist. If adequate lowering cannot be achieved on tolerated oral therapy, discuss with a paediatric or adult lipid specialist. PCSK9-inhibitor indications, regulatory approval and subsidy differ between jurisdictions, and paediatric use in Australia requires careful consideration of current TGA, PBS and specialist-access requirements alongside the limited long-term paediatric safety data.

Treatment pathway for an adolescent with heterozygous familial hypercholesterolaemia: statin monotherapy first, then ezetimibe, then specialist escalation, targeting LDL-C below 3.5 millimoles per litre or a reduction of at least 50 per cent. — Stepwise escalation in adolescent heterozygous FH. Agent, dose and timing should follow current Australian product information and specialist advice.

Baseline assessment and monitoring

Before treatment, confirm the familial variant and baseline lipid profile, exclude important secondary contributors to hypercholesterolaemia — thyroid dysfunction, renal and hepatic disease, nephrotic-range proteinuria — and document liver enzymes, creatine kinase, renal function, glucose status, growth and pubertal development.

Repeat the lipid profile and relevant safety bloods after initiation and after each dose change. Recheck creatine kinase if muscle symptoms develop. Track weight, growth, pubertal progress and general wellbeing at review. A single rigid testing interval does not suit every patient; the principle is that each change in therapy is followed by a reassessment. Before concluding that therapy has failed, review adherence, dose, tolerability, access and the adolescent's understanding of why treatment is needed.

Long-term statin safety in children with familial hypercholesterolaemia

Parents almost always ask some version of "is it safe to start this at 14?" The most useful answer is that the same cohort of children has now been followed for two decades, in three linked publications.

The original study randomised 214 children with FH — a pathogenic LDLR or APOB variant documented in 98% — to pravastatin or placebo for two years. That trial found no adverse effect on growth, pubertal development, hormone levels, or liver and muscle enzymes. A ten-year follow-up reported normal growth and sexual maturation. At 20 years, 184 of the original 214 patients (86%) were reassessed alongside 77 unaffected siblings, and no statin-attributable safety signal had emerged.

The efficacy findings at 20 years are what make the safety data worth acting on. Carotid intima–media thickness progression was 0.0056 mm/year in the treated FH patients versus 0.0057 mm/year in their unaffected siblings — effectively no excess. Compared with their 156 affected parents, for whom statins only became available in adult life, cumulative cardiovascular events by age 39 were 1% versus 26%, and cardiovascular death 0% versus 7%.

The less-quoted finding

Despite two decades of treatment, mean LDL-C in that cohort had fallen only 32% from baseline, and just 20% reached an LDL-C below 2.6 mmol/L. Starting early is necessary but not sufficient — sustained titration, adherence support and structured transition to adult care are what convert an early start into a lifetime of lower exposure. This is the argument for planning follow-up now rather than assuming the first prescription has solved the problem.

Two caveats to state plainly when quoting these numbers: the randomised phase lasted only two years, so the 20-year comparison is observational; and the parental comparator is intergenerational rather than contemporaneous, so differences in smoking, blood pressure control and background care contribute alongside statin exposure. Neither undermines the direction of the finding, but both matter if a colleague pushes back.

Lipoprotein(a): test her, but do not assume her result

The father's Lp(a) of 162 mg/dL is a compelling reason to measure hers. It is not evidence that she has inherited it. The familial FH variant and the genetically determined Lp(a) trait are inherited independently. She has inherited FH; whether she has also inherited elevated Lp(a) remains unknown until it is measured.

Measure Lp(a) once. A single measurement is usually sufficient once the patient is clinically stable, as levels are largely genetically set and stable through life. Repetition may be appropriate where the result is borderline, discordant with the clinical picture, or obtained during an illness or other potentially modifying condition.
An elevated result does not change first-line therapy — Lp(a) is not meaningfully lowered by statins. If her own Lp(a) is elevated, it acts as an additional risk modifier and strengthens the rationale for sustained, intensive LDL-C lowering.
It carries its own family implications, tracking through the pedigree independently of the FH variant.

The index case is not finished either

Her father remains a very-high-risk secondary-prevention patient with markedly elevated Lp(a). No pharmacotherapy is currently approved specifically to lower Lp(a) and improve cardiovascular outcomes, so management centres on intensive control of LDL-C and every other modifiable risk factor while targeted therapies remain investigational. (Lipoprotein apheresis can substantially lower Lp(a) in selected very-high-risk settings.) Diagnosing the child should not become the reason his own review lapses.

The wider family: cascade and counselling

Cascade testing extends outward from the index case — to his children first, then his siblings, parents and their children. Each confirmed case opens a further branch; each is a person who feels entirely well.

Cascade genetic testing radiating from an index case with familial hypercholesterolaemia to first-degree relatives and then to second-degree relatives, with interpretation of variant detected and variant not detected results. — Cascade testing radiates outward from the index case. A negative targeted result excludes the familial variant only — it does not account for a markedly elevated LDL-C.

The immediate household in this family resolved as follows:

Each child's risk is independent — one affected, one not, is one outcome of a 50% per-child probability, not a rule that half must be affected. The mother is not part of the paternal cascade and cannot inherit this variant; her lipid profile was obtained as independent screening.

Her mother's lipid profile was obtained not as part of the paternal genetic cascade — she cannot inherit her husband's variant — but as routine cardiovascular case-finding, and to identify any additional inherited or acquired lipid abnormality that could influence interpretation of the children's phenotype.

Interpreting a negative cascade result

A negative targeted result excludes inheritance of the documented familial variant. It does not explain a markedly elevated LDL-C. If the familial variant is absent but the phenotype remains severe, reassess secondary causes and seek specialist or genetics advice. A negative result also does not exclude polygenic hypercholesterolaemia, which is the commoner explanation for a moderately raised LDL-C in a variant-negative relative.

Counselling should accompany each step and should cover the psychological, reproductive and family implications of both positive and negative results. Under legislated protections effective from 8 October 2026, life insurers cannot solicit or use protected genetic information; a clinical diagnosis and other medical information may still be relevant to underwriting, so patients seeking individual insurance advice should be directed to current genetics or consumer guidance. An outdated blanket warning about insurance can inadvertently discourage precisely the testing this pathway depends on.

Counselling the family

Safety and monitoring

Paediatric statin data are reassuring: the randomised and ten-year follow-up data show no adverse effect on growth or pubertal development, and no safety signal has emerged at 20 years. Explain what is being monitored and why — this is often what the parents are most anxious about.

Reproductive counselling

At 14 this must be raised sensitively but explicitly: explain that statins are generally withheld during pregnancy and breastfeeding. Document the discussion, and revisit contraception and pregnancy planning as she matures, ideally with her directly.

Adherence and shared decision-making

Adolescence is when lifelong medication habits form or fail. Involve her in the decision rather than negotiating solely with her parents.

Transition to adult care

Plan a structured handover in late adolescence to minimise loss to follow-up during the transition from paediatric to adult care.

Lifestyle advice should be age-appropriate: regular physical activity and improved cardiorespiratory fitness, a heart-healthy dietary pattern, and a healthy weight. Avoiding smoking and vaping is one of the most important modifiable lifetime risk measures.

Initial management

Where the case stands

After discussion with the family, the 14-year-old was started on rosuvastatin 5 mg daily, with baseline safety bloods documented and a repeat lipid profile and liver enzymes planned to assess response and tolerability before considering titration or the addition of ezetimibe. Her Lp(a) has been requested.

Targeted cascade testing did not detect the familial LDLR variant in her sister, whose lipid profile was not suggestive of FH. Her mother's lipid profile did not identify an additional lipid disorder. Wider cascade testing through the paternal family — his siblings, parents, and their children — was recommended and is ongoing. Her father continues under specialist cardiology care as a very-high-risk secondary-prevention patient.

Follow-up biochemical results were not available at the time of publication.

Five practice points

Practice points

Recognise the index case. LDL-C above 5 mmol/L in an adult, premature coronary disease, tendon xanthomata, or a family history of early cardiac events.
Ask the family question at the first visit: "Who else in the family — including children — has had their cholesterol checked?"
Obtain the index case's genetic report and use it to request targeted cascade testing under MBS item 73353 for first- and second-degree relatives.
Add a one-off Lp(a) to the index case's panel and to that of each affected relative.
Refer children early. Specialist involvement streamlines paediatric initiation, target setting, escalation pathways and coordination across the family.

The one thing to take away

When you diagnose familial hypercholesterolaemia in an adult, you have not finished — you have found the entry point to a family. Testing the children is where the greatest number of life-years is saved, and in Australia that test is one a GP can order.

Frequently asked questions

At what age should a child with FH start a statin?

Australian guidance recommends considering statin therapy from approximately 8–10 years of age in heterozygous familial hypercholesterolaemia, with the decision individualised according to LDL-C level, family phenotype and other risk factors.

What LDL-C target applies to an adolescent with FH?

For those over 10 years with heterozygous FH, a practical goal is an LDL-C below 3.5 mmol/L or a reduction of at least 50% from baseline. A lower individual target may be considered with specialist input where the family history is particularly adverse.

Can a GP order genetic testing for familial hypercholesterolaemia?

A GP can request cascade testing for a known familial variant in a first- or second-degree relative under MBS item 73353, provided the index case's genetic result is available. Index-case testing under item 73352 requires a specialist or consultant physician request and has its own clinical eligibility criteria.

What does a negative cascade genetic test mean?

It excludes inheritance of the documented familial variant, but it does not explain a markedly elevated LDL-C and does not exclude polygenic hypercholesterolaemia. If the phenotype remains severe despite a negative targeted result, reassess secondary causes and seek specialist or genetics advice.

Why measure lipoprotein(a) in familial hypercholesterolaemia?

Lipoprotein(a) can add cardiovascular risk beyond the LDL burden and is largely genetically determined, so a single measurement is usually sufficient once the patient is clinically stable. An elevated level does not change first-line therapy but strengthens the case for sustained, intensive LDL-C lowering.

Are statins safe long-term in children?

The same cohort of 214 children with FH has been followed for 20 years. The original two-year randomised trial found no adverse effect on growth, pubertal development, hormone levels or liver and muscle enzymes; ten-year follow-up showed normal growth and maturation; and at 20 years no statin-attributable safety signal had emerged. Over the same period, carotid intima–media thickness progression matched that of unaffected siblings, and cardiovascular events by age 39 were 1% compared with 26% in their affected parents.

Referrals

Refer a patient or family for FH assessment

Heartcare Sydney provides FH diagnosis, coordination of cascade genetic testing across families, treatment initiation in adolescents and adults, and specialist escalation pathways. Consultations are available in English and Persian.

Refer a Patient

Related resources

Key references

Horton AE, Martin AC, Srinivasan S, et al. Integrated guidance to enhance the care of children and adolescents with familial hypercholesterolaemia: practical advice for the community clinician. J Paediatr Child Health 2022;58:1297–1312.
Watts GF, Sullivan DR, Hare DL, et al. Integrated Guidance for Enhancing the Care of Familial Hypercholesterolaemia in Australia. Heart Lung Circ 2021;30:324–49.
Luirink IK, Wiegman A, Kusters DM, et al. 20-Year Follow-up of Statins in Children with Familial Hypercholesterolemia. N Engl J Med 2019;381:1547–56.
Wiegman A, Hutten BA, de Groot E, et al. Efficacy and safety of statin therapy in children with familial hypercholesterolemia: a randomized controlled trial. JAMA 2004;292:331–7.
Kusters DM, Avis HJ, de Groot E, et al. Ten-year follow-up after initiation of statin therapy in children with familial hypercholesterolemia. JAMA 2014;312:1055–7.
Wiegman A, Gidding SS, Watts GF, et al. Familial hypercholesterolaemia in children and adolescents: gaining decades of life by optimizing detection and treatment. Eur Heart J 2015;36:2425–37.
Watts GF, Gidding SS, Hegele RA, et al. International Atherosclerosis Society guidance for implementing best practice in the care of familial hypercholesterolaemia. Nat Rev Cardiol 2023;20:845–69.
Medicare Benefits Schedule — item 73352 and item 73353 — genetic testing for familial hypercholesterolaemia.

Written consent for publication was obtained from the patient's parent or guardian, with the adolescent involved in the discussion. Details have been de-identified. This article provides general educational information based on current guidelines and does not replace individualised clinical judgement. Agents, doses, regulatory approvals and subsidy criteria should be confirmed against current Australian product information, TGA registration and PBS criteria at the time of prescribing.