Successful fenofibrate therapy for severe and persistent hypertriglyceridemia in a boy with cirrhosis and glycerol-3-phosphate dehydrogenase 1 deficiency

Identification of a novel heterozygous GPD1 missense variant in a Chinese adult patient with recurrent HTG-AP consuming a high-fat diet and heavy smoking

BACKGROUND

Glycerol-3-phosphate dehydrogenase 1 (GPD1) gene defect can cause hypertriglyceridemia (HTG), which usually occurs in infants. The gene defect has rarely been reported in adult HTG patients. In the present study, we described the clinical and functional analyses of a novel GPD1 missense variant in a Chinese adult patient with recurrent hypertriglyceridemia‑related acute pancreatitis (HTG-AP), consuming a high-fat diet and smoking heavily.

METHODS

Exome sequencing was used to analyze the DNA of the adult patient's blood sample. It was found that there was a new variant of GPD1 gene-p.K327N, which was verified by gold standard-sanger sequencing method. In vitro, the corresponding plasmid was constructed and transfected into human renal HEK-293T cells, and GPD1 protein levels were detected. A biogenic analysis was performed to study the population frequency, conservation, and electric potential diagram of the new variant p.K327N. Finally, the previously reported GPD1 variants were sorted and their phenotypic relationships were compared.

RESULTS

A novel heterozygous variant of GPD1, p.K327N (c.981G > C), was found in the proband. Furthermore, the patient's daughter carried this variant, whereas his wife did not carry the variant. The proband with obesity suffered eight episodes of HTG-AP from the age of 36 years, and each onset of AP was correlated to high-fat diet consumption and heavy smoking. In vitro, this variant exerted a relatively mild effect on GPD1 functions, which were associated with its effect upon secretion (~ 25% of secretion decreased compared with that of the wild-type); thus, eventually impairing protein synthesis. Additionally, 36 patients with GPD1 variants found in previous studies showed significant transient HTG in infancy. The proband carrying the GDP1 variant was the first reported adult with recurrent HTG-AP.

CONCLUSION

We identified a novel GPD1 variant, p.K327N, in a Chinese adult male patient with recurrent HTG-AP. The variant probably exerted a mild effect on GPD1 functions. The heterozygosity of this GPD1 variant, in addition to high-fat diet consumption and heavy smoking, probably triggered HTG-AP in the patient.

A very rare cause of hypertrygliseridemia in infancy: a novel mutation in glycerol-3-phosphate dehydrogenase 1 (GPD1) gene

OBJECTIVES

Transient infantile hypertriglyceridemia (HTGTI) is caused by mutations in the glycerol-3-phosphate dehydrogenase 1 (GPD1) gene. HTGTI is characterized by hypertriglyceridemia, hepatomegaly, hepatic steatosis and fibrosis in infancy. Here, we reported first Turkish HTGTI patient with a novel mutation of GPD1, having hypertriglyceridemia, hepatomegaly, growth retardation and hepatic steatosis. He is the first case who needs transfusion until 6th month in GPD1.

CASE PRESENTATION

A 2-month-27-day-old boy, who had growth retardation, hepatomegaly and anemia suffered to our hospital with vomiting. Triglyceride level was 1603 mg/dL (n<150). Liver transaminases were elevated and hepatic steatosis was developed. He needed transfusion with erythrocyte suspension until 6th month. Etiology could not be elucidated by clinical and biochemical parameters. A novel homozygous c.936_940del (p.His312GlnfsTer24) variant was detected in the GPD1 gene by Clinical Exome Analysis.

CONCLUSIONS

GPD1 deficiency should be investigated in the presence of unexplained hypertriglyceridemia and hepatic steatosis in children especially in infants.

Clinical characteristics and variant analyses of transient infantile hypertriglyceridemia related to GPD1 gene

Objective: Our study aims to summarize and analyze the clinical characteristics of transient infantile hypertriglyceridemia (HTGTI) and variants in the glycerol-3-phosphate dehydrogenase 1 (GPD1) gene and the effect of HTGTI on the protein structure of GPD1.

Methods: Retrospective analysis, using the general data, symptoms, signs, and auxiliary examinations, was performed on patients with HTGTI, which were confirmed by genetic testing in our hospital and reported cases online. The clinical data were analyzed using statistical and bioinformatic approaches.

Results: A total of 31 genetically confirmed HTGTI patients were collected from our hospital and cases reported in the literature. The clinical manifestations showed the median age of onset was 6.0 (1.9, 12.0) months. All the patients had normal psychiatric status, but 22.6% of them presented growth retardation and short stature, 93.5% had hepatomegaly, and 16.1% had splenomegaly. Just a few children were reported with jaundice, cholestasis, and obesity (3.2–6.5%). The laboratory investigations showed that 96.8% of them had hypertriglyceridemia (HTG) with a median level of 3.1 (2.1, 5.5) mmol/L, but only 30.0% had returned to normal during follow-up. In addition, 93.5% of patients had elevated alanine aminotransferase (ALT) with an average level of 92.1 ± 43.5 U/L, while 38.7% had hypercholesterolemia. Upon abdominal imaging, all patients presented fatty liver and liver steatosis, with 66.7% of patients showing hepatic fibrosis. Statistical differences in triglyceride (TG) level were observed in the ≤6 months group compared with the older groups and in the 13 months to 6 years group with &gt;6 years group (H = 22.02, P &lt; 0.05). The restricted cubic spline model showed that severe HTG decreased in the early stage of infants to the normal level; however, it rebounded again to a mild or moderate level after the following days. The genetic test revealed that the main variant types of the GPD1 gene were missense variants (51.6%), followed by splicing variants (35.5%) and nonsense variants (12.9%). Of patients, 87.1% had homozygous variants, with the most frequent loci being c.361-1G &gt; C and c.895G &gt; A.

Conclusion: The common manifestations of HTGTI were HTG, hepatomegaly, elevated liver transaminases, and hepatic steatosis in early infancy. However, the recurrence of aberrant HTG may pose long-term detrimental effects on HTGTI patients.

Case of GPD1 deficiency causing hypertriglyceridaemia and non-alcoholic steatohepatitis

We report a case of a young girl of South Asian descent presented with faltering growth, hepatomegaly, hypertriglyceridaemia and raised transaminases. Subsequent ultrasound scans identified fatty infiltration in her liver, and a liver biopsy showed fibrosis and steatosis. The patient's serum triglycerides normalised without intervention by the age of 28 months. At age 6, whole-exome sequencing of the patient's genome identified novel homozygous variants in the glycerol-3-phosphate dehydrogenase 1 (GPD1) gene, GPD1 c.500G>A (p.Gly167Asp), leading to a diagnosis of GPD1 deficiency.

Case Report: Identification of a Novel Homozygous Mutation in GPD1 Gene of a Chinese Child With Transient Infantile Hypertriglyceridemia

Transient infantile hypertriglyceridemia is a rare autosomal recessive disorder characterized by hypertriglyceridemia, hypohepatia, hepatomegaly, hepatic steatosis and fibrosis in infancy. Mutations in GPD1 gene are considered the causative factor but the underlying mechanism of this disorder is still enigmatic. To date, only 24 different GPD1 mutations have been reported in the literature worldwide with transient infantile hypertriglyceridemia or relevant conditions. Here we report a Chinese girl who developed hepatomegaly hepatic steatosis, elevated transaminase and hypertriglyceridemia from the age of 4 months. A novel homozygous variant c.454C>T (p.Q152*) was found in GPD1 gene by next-generation sequencing. This patient is the 3rd Asian reported with transient infantile hypertriglyceridemia. We summarized the clinical presentations of transient infantile hypertriglyceridemia and also expanded the spectrum of disease-causing mutations in GPD1.

Transient infantile hypertriglyceridemia with jaundice: A case report

RATIONALE

Transient infantile hypertriglyceridemia (HTGTI) is a rare autosomal recessive inherited disease caused by inactivating mutations in the glycerol-3-phosphate dehydrogenase 1 gene. To date, only a few patients have been reported worldwide. The symptoms of the affected individuals present a certain degree of transient hypertriglyceridemia, hepatomegaly, elevated liver enzymes, persistent fatty liver and hepatic fibrosis in early infancy. However, the clinical characteristics and pathogenesis of this disease are remain unclear.

PATIENT CONCERNS

A one month and twenty-five days old girl was admitted to hospital because of persisted jaundice and hepatomegaly for fifty days.

DIAGNOSE

The girl was diagnosed with HTGTI coincident with a noval mutation in glycerol-3-phosphate dehydrogenase 1.

INTERVENTION

She was advised to take low-fat diet and supplement of medium-chain fatty acids.

OUTCOMES

Her jaundice was gradually normal at the age of 4 months without any treatment, and hypertriglyceridemia were normal at the age of 13 months, but still had elevated transaminases and hepatic steatosis.

LESSONS

Jaundice may be a novel phenotype in HTGTI. The report contributes to the expansion of HTGTI's gene mutation spectrum and its clinical manifestations.