Introduction:
The most prevalent hereditary metabolic illness is Familial hypercholesterolemia (FH), a widespread condition of lipid metabolism. If untreated, it can cause early Coronary heart disease (CHD) due to high blood levels of Total cholesterol (TC) and Low-density lipoprotein cholesterol (LDL-C). A lifelong buildup of Low-density lipoprotein cholesterol (LDL-C) in plasma and early atherosclerosis may result from afflicted patients' inability to remove LDL particles from the circulation due to a genetic abnormality in the Low-density lipoprotein (LDL)-receptor (LDLR) pathway. If untreated, homozygous FH (HoFH) patients experience severe, life-threatening CHD and other vascular problems in late childhood and adolescence. This is because the cumulative cholesterol burden is considerably higher in HoFH patients.
Nearly 90 % of FH patients with genetic diagnoses have a mutant LDLR as the underlying abnormality, which causes plasma LDL-C levels to more than double. Apolipoprotein B, the main protein of LDL particles, is encoded by a gene that is mutated in around 10 % of FH patients. A mutation in the gene encoding Proprotein convertase subtilisin/kexin type 9 (PCSK9), which is responsible for breaking down LDLR, is seen in less than 1 % of cases. Homozygous mutations in the LDL receptor adaptor protein (LDLRAP1) gene can also cause an FH phenotype in the uncommon Autosomal recessive form (ARH). Heterozygous FH (HeFH) is believed to have a frequency of 1:200–500, although more recent data indicate that the prevalence may be closer to 1:100–250.
What Is the Role of Phenotypic Expression of Fh in Children and Adolescents?
The common physical manifestations of FH in children, such as corneal arcus, xanthelasma, and xanthomas, are uncommon, notably in the Achilles tendons, extensor tendon on the dorsum of the hand, and interdigital. If one or more of these conditions exist, FH is almost pathognomonic. The Achilles tendon, however, is far more prone to discomfort.
Despite the rarity of cardiovascular events in children, the vessel wall exhibits functional and structural alterations in those who have FH. Children with FH had increased and impaired Carotid intima-media thickness (cIMT) and Flow-mediated dilatation (FMD), two surrogate indicators for atherosclerosis, in comparison to healthy controls. According to current studies, the difference in mean cIMT between children with FH and unaffected siblings may even be noticeable as early as the age of 8 years.
What Is Children’s HeFH Screening?
A child from a family where HeFH has been identified or suspected (based on clinical/genetic criteria), a child from a family with a history of early CVD (before the age of 55 and 60 in men and women, respectively), or a child whose parents have primary hypercholesterolemia are at least three of the circumstances in which a child can be suspected of having FH. This highlights the significance of evaluating the family history of all children for cholesterol levels, CVD, and known or suspected associated diseases. Children with suspected HeFH should be screened starting at age 5; screening for HoFH should be done when clinically suspected (both parents affected or xanthoma present) and as early as possible. If DNA testing is available, cascade screening of families is recommended using both a phenotypic and genotypic strategy. If DNA testing is not available, a phenotypic strategy based on country, age-and gender-specific LDL-C levels should be used. Screening methods for adolescents and children with Familial hypercholesterolemia (FH) are
-
Age Range: Screening of the whole population for a certain age range.
-
Selective Screening: It involves conducting tests on a particular, high-risk population.
-
Cascade Screening: Examining all members of the family, including children, starting with the index case (parent).
-
Reverse Screening: Reverse screening is done on family members, starting with the index case (child or teenager).
-
Child-Parent Screening: Screening of parents once children of a certain age have passed.
How Is FH Identified in Pediatric Patients?
The gold standard for diagnosis in children should ideally be the identification of the mutation that causes FH. However, genetic testing is not always accessible. The presence of an elevated LDL-C level, together with a family history of early CVD or elevated LDL-C levels congruent with FH in this circumstance, can be used to phenotypically identify FH in children. FH diagnosis in children and teenagers is done by:
-
The two most crucial critical selective screening indicators are increased LDL-C values and a positive family history of early CHD.
-
Blood cholesterol tests should be used to make a phenotypic diagnosis. A diagnosis of FH is strongly indicative if LDL-C > 190 mg/dL on two separate blood samples taken at baseline and three months after receiving nutrition and lifestyle therapy. A highly probable diagnosis of FH is indicated by LDL-C > 160 mg/dL, a positive family history of early CHD in first-degree relatives, and high blood cholesterol in first-degree relatives. A parent with a hereditary diagnosis of FH and an LDL-C level above 130 mg/dL are signs of probable FH.
-
It is important to rule out any secondary causes of hypercholesterolemia.
-
The gold standard of diagnosis is DNA testing. Children and/or teenagers should also undergo genetic testing in cases where a harmful LDL-R mutation has been discovered in a first-degree relative.
-
A kid with hypercholesterolemia (even moderate cases) should have genetic testing for FH and Lp(a) levels performed in case of a parent's death from CHD.
Conclusion:
Early detection of FH in children is crucial for preventing atherosclerosis at its earliest stages and allowing for therapy and lifestyle changes that can still provide the greatest benefit. Decades of healthy life can be gained with the early discovery and treatment of FH in childhood and adolescence. Although much experience has been acquired over the past 20 years and many solutions to problems that arise in screening programs have been published, there are still several evidence gaps that need to be addressed. This can enhance current screening and treatment approaches for kids with FH, which must be situation-specific. A multidisciplinary approach incorporating pediatric, adult, and primary care physicians with a focus on the best methods of identification and treatment will ultimately alter the course of this prevalent and fatal disease.
