Study of the Week: Lysosomal Acid Lipase Deficiency in Japan

Welcome to Study of the Week from Patient Worthy. In this segment, we select a study we posted about from the previous week that we think is of particular interest or importance and go more in-depth. In this story we will talk about the details of the study and explain why it’s important, who will be impacted, and more.

If you read our short form research stories and find yourself wanting to learn more, you’ve come to the right place.


This week’s study is…

Screening for lysosomal acid lipase deficiency in Japanese patients with suspected familial hypercholesterolemia

We previously published about this research in a story titled “Study: Detection of Lysosomal Acid Lipase Deficiency in Japan FH Patients” which can be found here. The study was originally published in the scientific journal Atherosclerosis. You can read the abstract of the study here

What Happened?

Lysosomal acid lipase deficiency and familial hypercholesterolemia are two underdiagnosed conditions that can present similarly in some patients. Examples of similarities include a high level of low-density lipoprotein cholesterol (LDL-C) and cardiovascular disease relatively early in life. Research has suggested a prevalence rate for lysosomal acid lipase deficiency ranging from 1 in 9000 to 1 in 170000 people. However, little research has been done in other countries, such as Japan. In this study, researchers sought to understand the prevalence of the disorder by screening patients in Japan living with a suspected diagnosis of familial hypercholesterolemia.

The researchers were concerned that cases of lysosomal acid lipase deficiency were being overlooked in Japan. The study involved a total of 553 patients who were screened for the condition using a dried blood spot test. This test measured activity of lysosomal acid lipase, as low levels of activity is a key indicator of the disease. Of the patients that were tested, only one displayed low activity, though no patient had activity less than the mean of patient controls. This patient also displayed other possible signs, such as liver dysfunction and very high LDL-C that was resistant to statin treatment.

This individual received further genetic testing, which found two novel mutations. The patient was ultimately diagnosed with heterozygous compound lysosomal acid lipase deficiency and began treatment with enzyme replacement therapy. The authors concluded that the result could suggest lower prevalence of the disease among Japanese patients with suspected familial hypercholesterolemia in comparison to European populations. They also suggested that screening for lysosomal acid lipase deficiency could nevertheless be useful, and that genetic testing can help diagnose the illness when lysosomal acid lipase activity level isn’t severely affected.

About Lysosomal Acid Lipase Deficiency (LALD)

Ulcerative colitis is a long-term condition which is characterized by the appearance of ulcers and generalized inflammation of the rectum and colon. The exact cause of the condition remains a mystery, but there do appear to be some risk factors, such as family history, diet, and exposure to the medication isotretinoin. Smoking appears to have a slightly protective effect. Symptoms can include anemia, bloody diarrhea, weight loss, fever, and abdominal pain. They tend to appear in a relapsing-remitting pattern. In severe disease there is a risk of serious complications, such as megacolon or inflammatory disease in other parts of the body. The risk of colon cancer is also elevated. Treatment may include dietary changes, medication to control inflammation, and, when complications appear, surgery. To learn more about ulcerative colitis, click here.

About Familial Hypercholesterolemia

Familial hypercholesterolemia is a condition of elevated, abnormally high levels of LDL cholesterol that is caused by a hereditary genetic mutation. The mutation that causes the condition affects the LDLR gene which normally codes for a protein that removes LDL from the bloodstream. The primary symptoms are elevated LDL cholesterol, deposits of cholesterol in certain areas of the body (eyelids, iris, and tendons of the arms and legs), and early onset cardiovascular issues, such as coronary artery disease, strokes, heart attack, and atherosclerosis. While once considered rare, it is likely that many people with the condition live undiagnosed. Treatment may include statins or other medications, liver transplant, or other surgical operations. The true prevalence of familial hypercholesterolemia remains unknown. To learn more about familial hypercholesterolemia, click here.

Why Does it Matter?

The scientists learned that prevalence rates for LALD appear to vary between different populations. Less than 10 people have been diagnosed with the disease in Japan. They also discovered missense mutations in the case that they found that hadn’t been attributed to the disease before.

Overall, the findings from the study revealed new information about the condition, as well as how screening methods, such as combination of genetic testing and blood tests, could help improve rates of diagnosis.


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