Shin Koike (LLM expected 2025), student fellow, Center for Law and the Biosciences

Introduction

Direct-to-consumer (DTC) genetic testing is now widely available in the United States (U.S.), with over 250 companies reportedly offering such services, and the market was estimated at USD 2.43 billion in 2024, with projections reaching USD 17.35 billion by 2033.[1] Some of these companies are now seeking to expand into the Japanese market. However, unlike the U.S., where certain moderate- to high-risk DTC genetic tests are subject to FDA review and approval,[2] Japan’s regulatory framework remains complex and lacks clarity, posing significant potential barriers to market entry. One major source of these barriers is the regulatory scheme governing medical practice under the Medical Practitioners’ Act (Act No. 201 of July 30, 1948), which raises the critical question of whether the provision of DTC genetic testing constitutes medical practice and, therefore, must be conducted by a licensed physician.

Medical Practitioners’ Act

The Medical Practitioners’ Act provides the following:

(Article 17)

“No person except a medical practitioner may engage in medical practice.”[3]

Under this provision, if DTC genetic testing services constitute “medical practice,” they must be provided by a licensed physician. In cases of a violation, both the individual and the company would be subject to criminal penalties.[4] However, as will be analyzed below, the definition of “medical practice” remains ambiguous, and this ambiguity has led to misinterpretations in the context of DTC genetic testing.

Definition of “Medical Practice” by the Supreme Court and the MHLW

First, in a case concerning whether tattooing constitutes “medical practice,” Japan’s Supreme Court ruled as follows:

• Article 17 of the Medical Practitioners’ Act is interpreted as a provision intended to prevent risks to public health and hygiene that may result when medical care or health guidance, which are duties of licensed physicians, is provided by unqualified individuals who are not doctors.
• The term “medical practice” as defined in Article 17 of the Act refers to medical acts that fall within the scope of medical care and health guidance, which, if not performed by a licensed physician, may pose a risk of harm to public health and hygiene.
• Whether a particular act constitutes a “medical act” under Article 17 of the Act should be determined not only based on the method and effects of the act but also by considering factors such as its purpose, the relationship between the actor and the recipient, the specific circumstances under which the act is performed, prevailing conditions, and how it is perceived in society. The determination should be made in accordance with social norms.[5]

As the Supreme Court emphasized, determining whether a particular act constitutes “medical practice” requires analyzing whether performing it without a licensed physician may pose a risk to public health and hygiene, considering various facts.

Second, in alignment with the Supreme Court’s decision, the Ministry of Health, Labour and Welfare (MHLW) defines “medical practice” as follows:

“‘Medical practice’ refers to the acts that, if not carried out based on a physician’s medical judgment and expertise, may cause harm or pose a risk of harm to the human body, with the intent to do so repeatedly and continuously. Whether a particular act constitutes a medical act must be determined on a case-by-case basis, taking into account the specific nature of each act.”[6]

In summary, both the Supreme Court and the MHLW underscore two essential factors in defining “medical practice”:

• considering various contextual factors, and
• analyzing whether performing the act without a licensed physician may cause harm or pose a risk to human health or life.

MHLW’s Questionable Application of the Definition of Medical Practice to DTC Genetic Testing

The MHLW explains the relationship between medical diagnosis and DTC genetic testing that provides potential disease risk information as follows:

“In DTC genetic testing businesses that provide disease risk information along with consumers’ genotypes:

• When the test is limited to multifactorial diseases, where not only genetic factors but also environmental factors play a significant role in disease onset, and
• When the test merely compares statistical data with test results,

it cannot be considered a ‘diagnosis’ and does not constitute a medical act. On the other hand, actions that involve identifying individual consumers and predicting or assessing their disease risks constitute a ‘diagnosis’ and fall under the category of medical acts.”[7]

According to this interpretation, for instance, providing disease risk information for multifactorial diseases such as diabetes based solely on comparisons to statistical data does not constitute “medical practice” because they are not considered medical diagnoses.

However, as both the Supreme Court and even the MHLW itself have emphasized, the fundamental criterion for determining whether an act constitutes “medical practice” is whether performing it without a licensed physician may cause harm or pose a risk to human health or life. The MHLW’s current approach—focusing primarily on whether a test qualifies as a diagnosis—is therefore questionable. Instead, the assessment should focus on the potential risks posed by the specific DTC genetic test in question.

Potential Risks Imposed by DTC Genetic Testing

It has been pointed out that DTC genetic testing presents several potential risks, including discrimination or stigmatization based on genetic test results and unnecessary medical interventions prompted by inaccurate or misleading results.[8] Among these risks, the most serious is the possibility that general consumers may misinterpret their test results and make inappropriate healthcare decisions, such as failing to seek necessary medical treatment.

This risk persists even if companies provide thorough explanations of the purpose and limitations of DTC genetic testing. For instance, consider a false negative scenario in which a test-taker receives results indicating that their genetic group has a statistically low risk of developing diabetes. What would they do next? Even if the test provider explains that the results are not a diagnosis and recommends consulting a doctor, how many individuals would actually seek medical advice or undergo further testing?

Regardless of how carefully companies explain the limitations of these tests, some consumers take DTC genetic tests with the expectation of screening for diseases. Given this reality, the assumption that consumers fully understand the implications of their test results and make truly informed healthcare decisions may be more of a legal fiction than a practical reality.

Conclusion

Given the definitions provided by the Supreme Court and the MHLW, it is reasonable to conclude that whether the provision of DTC genetic testing constitutes “medical practice” depends on the level of risk posed by the specific test—regardless of whether the test concerns a multifactorial disease or is based solely on statistical comparisons. Since potential risks posed by DTC genetic testing can be mitigated through proper counseling by a physician, regulating such services as medical practice—and requiring that they be provided under the supervision of a licensed doctor—would be both logical and effective. Indeed, as of 2017, several European countries—Austria, Cyprus, the Czech Republic, Estonia, Finland, France, Germany, Greece, Hungary, Italy, Latvia, Lithuania, Norway, Slovakia, Slovenia, and Spain—require genetic counseling for certain types of genetic tests.[9] Requiring physician involvement for certain moderate- to high-risk DTC genetic tests would align with these global regulatory trends.

In light of these considerations, the MHLW should shift its focus to the risks posed by DTC genetic testing. Furthermore, to eliminate regulatory ambiguity and provide clear expectations for companies seeking to enter the Japanese market, it should clarify which types of DTC genetic testing should be regulated as medical practice and required to be provided through a physician.

Notes

[1] BioSpace, “Direct-to-Consumer Genetic Testing Market Rising Rapidly at CAGR 24.43%,” April 23, 2024, https://www.biospace.com/direct-to-consumer-genetic-testing-market-rising-rapidly-at-cagr-24-43-percent

[2] The U.S. Food and Drug Administration, “Direct-to-Consumer Tests,” https://www.fda.gov/medical-devices/in-vitro-diagnostics/direct-consumer-tests

[3] The Ministry of Justice, English translation of Medical Practitioners’ Act, https://www.japaneselawtranslation.go.jp/ja/laws/view/3992

[4] In cases where a representative, agent, employee, or other personnel of a corporation violates this provision, (a) the individual would be subject to imprisonment with work for up to three years, a fine of up to one million yen, or both; and (b) the corporation would be subject to a fine of up to one million yen (Article 31, Paragraph 1, Item 1 and Article 33-3 of the Medical Practitioners’ Act).

[5] The Judgment by the Supreme Court of Japan (Keishu Vol. 74, No. 6, at 581) dated on September 16, 2020, https://www.courts.go.jp/app/hanrei_jp/detail2?id=89717. The translation is an unofficial version by the author.

[6] “Interpretation of Article 17 of the Medical Practitioners’ Act, Article 17 of the Dental Practitioners’ Act, and Article 31 of the Act on Public Health Nurses, Midwives and Nurses (Notification)” issued by the MHLW on July 26, 2005. The translation is an unofficial version by the author. https://www.mhlw.go.jp/web/t_doc?dataId=00tb2895&dataType=1&pageNo=1

[7] Explanatory Material on the Direct-to-Consumer (DTC) Genetic Testing Business, Presented at the 7th Meeting of the Task Force on the Promotion of the Practical Application of Genomic Medicine on March 30, 2016, https://www.mhlw.go.jp/file/05-Shingikai-10601000-Daijinkanboukouseikagakuka-Kouseikagakuka/160330_tf_s2.pdf

[8] Hogarth S, Javitt G, Melzer D. The current landscape for direct-to-consumer genetic testing: legal, ethical, and policy issues. Annu Rev Genomics Hum Genet. 2008;9:161-82. doi: 10.1146/annurev.genom.9.081307.164319. PMID: 18767961.

[9] Kalokairinou L, Howard HC, Slokenberga S, Fisher E, Flatscher-Thöni M, Hartlev M, van Hellemondt R, Juškevičius J, Kapelenska-Pregowska J, Kováč P, Lovrečić L, Nys H, de Paor A, Phillips A, Prudil L, Rial-Sebbag E, Romeo Casabona CM, Sándor J, Schuster A, Soini S, Søvig KH, Stoffel D, Titma T, Trokanas T, Borry P. Legislation of direct-to-consumer genetic testing in Europe: a fragmented regulatory landscape. J Community Genet. 2018 Apr;9(2):117-132. doi: 10.1007/s12687-017-0344-2. Epub 2017 Nov 18. PMID: 29150824; PMCID: PMC5849704.