Homozygous phytosterolemia and a literature review: A case report

Table 1 Patient’s blood lipid profile in response to changes in diet, exercise, and ezetimibe

Treatment	Total cholesterol (mmol/L)	Low-density lipoprotein cholesterol (mmol/L)	Triglyceride (mmol/L)	High density lipoprotein cholesterol (mmol/L)
Normal lifestyle	9.5	6.3	2.3	1.1
Exercise and dietary	6.1	4.0	1.4	1.3
Statin	6.5	4.6	0.8	1.2
Ezetimibe and dietary	4.6	2.8	1.5	1.2

Table 2 Mutations detected in the patient by whole exome sequencing

Gene	Chromosome location	Variation	Homozygous/heterozygous	Pathogenicity
ABCG5	chr2: 44050063	c.1336C>T (p.Arg446Ter)	Homozygous	Pathogenic
APOB	chr2: 21252807	c.1433G>A (p.Cys478Tyr)	Heterozygote	Unknown
APOB	chr2: 21228437	c.11303T>C (p.Ile3768Thr)	Heterozygote	Unknown

Table 3 Patient’s plasma sterol profiles showed significantly increased levels of dihydrocholesterol, dehydrocholesterol, canola oil sterols, and glutamine and glutaminol, suggesting phytosterolemia

Inspection item	Results	Units	Hint	Reference range
Squalene	0.76	μmol/L	Normal	0.300-4.00
Cholestanol	78.37	μmol/L		0.01-10.00
Desmosterol	5.78	μmol/L		0.30-5.00
Lathosterol	1.75	μmol/L	Normal	0.01-12.50
Campesterol	319.76	μmol/L		0.01-10.00
Stigmasterol	32.60	μmol/L		0.10-8.50
Sitosterol	307.79	μmol/L		1.00-15.00

Table 4 ABCG5 mutation in the patient’s parents and its validation

Relationship	Gene	Homozygous/heterozygous	Genotype	Verification result
Father	ABCG5 c.1336C>T	Heterozygote	CT	Positive
Mother	ABCG5 c.1336C>T	Heterozygote	CT	Positive