Neutral Lipid Storage Disease with Myopathy (NLSD-M)

November 26, 2023

 

NLSD-M is an ultra-rare genetic disease inherited in autosomal recessive fashion. This disease has a long history. Seventy years have passed since the first description of this disease by Professor Jordans in 1953. Symptoms of NLSD-M start at young and middle adult ages. Patients with NLSD-M suffer from slowly but irreversible and progressive disabling symptoms. No effective therapy is available. To find and develop therapies, this Non Profit Organization is launched.

 

In 2007, Professor Judith Fischer identified the genetic cause of NLSD-M as mutations in PNPLA2 gene, which encodes Adipose Triglyceride Lipase (ATGL). ATGL is an essential enzyme which break down triglyceride (TG) for mitochondrial b-oxidation to produce cellular energy. When both alleles of PNPLA2 are mutated, NLSD-M occurs. Patients’ muscles become fatty and lose power. As shown in Figure 1, there are no common mutations for NLSD-M found. A variety kind of mutations expanding the entire PNPLA2 gene have been identified (Figure 1), which makes it difficult to develop gene editing therapy.

 

So far, approximately ~100 patients with NLSD-M haven been identified (Figure 2). Patients with NLSD-M are distributed globally. Italy and China have 20~50 patients. Japan has several. Other countries have a couple of patients.

 

One of the reasons why such a small number of patients have been identified is un-awareness or less information of this disease. Primary and even expert physicians or other medical professionals do not know this disease well. In fact, many patients with NLSD-M have been suffering from mis-, un-, and delayed diagnosis. It often takes a couple of decades for patients to receive proper diagnosis.

 

However, there is a big hit for the diagnosis in patients’ blood (Figure 3). Almost all neutrophils in patients with NLSD-M possess multiple cytoplasmic vacuoles of lipid called Jordans’ anomaly. This appears before the myopathy symptom is initiated. At a glance, physicians or medical professionals easily would note this abnormality. In addition, it has been reported that most hematology analyzers can theoretically detect Jordans’ anomaly.

 

I wish all patients with NLSD-M and their family members have hope, success, and a fruitful future. Please do not give up.

 

For more information, please see the following links as well:

Neutral lipid storage myopathy - About the Disease - Genetic and Rare Diseases Information Center (nih.gov)

https://www.orpha.net/consor/cgi-bin/OC_Exp.php?lng=en&Expert=98908

 

Global cooperation is highly appreciated.

 

Thank you very much.

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Ken-ichi Hirano, MD, PhD

Department of Triglyceride Science, Graduate School of Medicine,

Osaka University, Osaka, Japan

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Elena Pennisi, MD, PhD

Neuromuscular and Rare Neurological Disease Center, San Filipo Neri Hospital, Rome, Italy

 

Daisaku Nakatani, MD, PhD

Global Clinical Research Support Office, Department of Medical Innovation,

Osaka University Hospital, Osaka, Japan

 

Corrado Angelini, MD, PhD

Department of Neurosciences, Padova University Graduate School of Medicine, Padova, Italy