Fabry disease is a rare, inherited condition that can affect multiple organs, including the heart, kidneys, and nervous system. Many people with Fabry disease live for a period of time without receiving disease-specific treatment, for example because treatment criteria have not yet been met. There is limited knowledge about how patients experience this period without treatment.

The purpose of this study is to improve understanding of how adults with Fabry disease who are not yet receiving disease-specific treatment experience their quality of life, their daily lives, and their contacts with health care services.

This is a national interview study in which participants will take part in one individual digital interview lasting approximately 45-60 minutes. During the interview, participants will be invited to describe their experiences in their own words, including symptoms, how the disease affects everyday life, psychological and emotional well-being, and experiences of follow-up and support from health care providers. Participants will also complete a short questionnaire with basic background information, such as age, education, and living situation.

By collecting and analyzing patients' own narratives, the study aims to identify needs, challenges, and support resources during the period without treatment. The results are expected to contribute to increased knowledge and to the development of more person-centered care for individuals living with Fabry disease.

Fabry disease is a rare X-linked lysosomal storage disorder caused by pathogenic variants in the GLA gene, leading to deficiency of the enzyme alpha-galactosidase A. As a result, globotriaosylceramide (Gb3) accumulates in cells and tissues, causing progressive involvement of multiple organ systems, including the heart, kidneys, and central nervous system. Clinical manifestations and disease severity vary considerably between individuals and between sexes.

Disease-specific treatment options, such as enzyme replacement therapy and chaperone therapy, are available for Fabry disease. However, a subgroup of patients does not yet receive such treatment, either because established treatment criteria are not fulfilled or for other medical reasons. Patient experiences during this untreated period are insufficiently described in the current literature.

This study is a national, qualitative interview study aiming to describe how adult patients with Fabry disease who are not receiving disease-specific treatment experience their quality of life, disease situation, and interactions with health care services. The study is conducted in collaboration between the two Swedish national high-specialty care centers (National Highly Specialized Care, NHV) for Fabry disease at Sahlgrenska University Hospital in Gothenburg and Karolinska University Hospital in Stockholm.

Participants are recruited through the respective NHV clinics. After providing written informed consent, each participant takes part in a single individual semi-structured interview. Interviews are conducted digitally and last approximately 45-60 minutes. The interview guide covers topics such as symptoms and impact on daily life, psychological and emotional experiences, perceptions of health care follow-up and communication, involvement in care decisions, expectations regarding potential future treatment, and the impact of Fabry disease within the family.

Interviews are audio-recorded, transcribed verbatim, and de-identified prior to analysis. No information is obtained from medical records. In addition to the interview, participants complete a short questionnaire providing basic demographic information.

Data are analyzed using qualitative content analysis at both manifest and latent levels, applying an inductive approach. Through systematic analysis of participants' narratives, categories and overarching themes are developed to capture shared experiences, variations, and patterns in how individuals experience living with Fabry disease without current disease-specific treatment.

The study is expected to generate in-depth knowledge of patients' experiences during the untreated phase of Fabry disease and to inform the development of more person-centered follow-up and support within highly specialized care for rare diseases.

Inclusion Criteria:

• Age 18 years or older
• Confirmed diagnosis of Fabry disease
• Followed at a National Highly Specialized Care (NHV) center for Fabry disease in Sweden (Sahlgrenska University Hospital or Karolinska University Hospital)
• Not currently receiving disease-specific treatment for Fabry disease (such as enzyme replacement therapy or chaperone therapy)
• Treatment may be considered in the future
• Ability to understand and speak Swedish
• Ability and willingness to provide written informed consent

Exclusion Criteria:

• Current or planned disease-specific treatment for Fabry disease
• Disease-specific treatment deemed permanently not indicated due to other medical conditions
• Actively declined an offered disease-specific treatment
• Inability to participate in a qualitative interview

The study population consists of adult patients diagnosed with Fabry disease who are not currently receiving disease-specific treatment. Participants are followed at national highly specialized care centers in Sweden and represent individuals living with Fabry disease during a period without active treatment.

The study is qualitative, based on audio-recorded interviews and narrative data.