ENA research team at Medizinische Hochschule Hannover, working in collaboration with Renji Hospital in Shanghai, has achieved a major milestone in medical science by successfully repairing the underlying genetic defect in patients with alpha-1 antitrypsin deficiency. Using advanced base-editing technology, the investigators targeted and corrected the specific point mutation within the liver cells of seven affected individuals. This targeted approach restores the body’s ability to produce functional protective protein without inducing double-strand DNA breaks. Initial findings regarding the safety and therapeutic efficacy of this gene correction have now been published in the scientific journal Journal of Hepatology. For individuals living with this severe hereditary disorder, the breakthrough offers real hope of replacing lifelong weekly intravenous infusions with a single precise intervention.
Understanding Alpha-1 Antitrypsin Deficiency and Its Clinical Manifestations
Alpha-1 antitrypsin deficiency is a hereditary metabolic disorder caused by a specific genetic mutation. Under normal physiological conditions, the protective protein alpha-1 antitrypsin is produced predominantly in the liver and transported through the bloodstream to the lungs. There, its primary role is to protect delicate pulmonary tissue from being broken down by the body’s own inflammatory enzymes. When the genetic code contains an error, the liver produces an abnormal protein or fails to release sufficient amounts into circulation.
Patients suffering from this condition frequently experience persistent shortness of breath, chronic coughing, and decreased physical endurance. Because these clinical manifestations are largely non-specific, the underlying disorder is very often misdiagnosed in its early stages. According to Dr. Nora Drick from the Department of Respiratory Medicine, many individuals are initially diagnosed with bronchial asthma or chronic obstructive pulmonary disease. This delay in accurate identification allows tissue damage to progress unchecked over several years.
Over time, the lack of functional protective protein leads to severe long-term complications in both the respiratory and hepatic systems. In the lungs, progressive destruction of alveolar walls results in pulmonary emphysema, while abnormal protein accumulation in liver cells can cause liver fibrosis and cirrhosis. The condition affects an estimated 120,000 people across Europe, with severe phenotypes causing debilitating illness. For patients with advanced end-stage organ failure, organ transplantation has historically remained the only available treatment option.
Current Standard Diagnostic and Therapeutic Approaches in Germany
In Germany, modern diagnostic protocols for suspected metabolic lung and liver disorders rely on comprehensive laboratory testing and precise molecular genetics. Specialists at leading university hospitals such as Medizinische Hochschule Hannover perform blood tests to quantify circulating alpha-1 antitrypsin levels and identify specific genetic alleles. High-resolution pulmonary imaging and liver elastography are routine procedures used to assess the exact degree of organ involvement.
Until now, conventional medical science possessed no curative treatments capable of rectifying the underlying genetic defect. Standard management has focused primarily on slowing disease progression and mitigating secondary symptoms. For individuals with the severe form of the disorder who produce no functional protective protein, doctors prescribe lifelong augmentation therapy. This treatment requires patients to receive intravenous infusions of concentrated human alpha-1 antitrypsin protein every single week.
While weekly augmentation therapy helps protect lung tissue to a certain degree, it represents a substantial burden for affected individuals. Patients must structure their entire personal and professional lives around lifelong weekly clinic visits or home infusions. Furthermore, augmentation therapy cannot reverse existing organ damage or halt subtle disease progression entirely. Consequently, German medical researchers have long sought definitive solutions that directly target the genetic source of the illness.
The Breakthrough Base-Editing Technique Developed by MHH Researchers
The novel therapeutic strategy developed by researchers at Medizinische Hochschule Hannover relies on precision gene correction rather than traditional gene replacement. Led by Prof. Dr. Michael Ott, senior consultant at the Department of Gastroenterology, Hepatology, Infectious Diseases and Endocrinology and head of the Laboratory for Cell and Gene Therapy, the team utilized modified CRISPR/Cas9 technology. Known as base editing, this biotechnological tool can correct a single defective building block—or base—in the DNA of liver cells with extraordinary accuracy.
Unlike conventional gene therapy methods that introduce an extra gene copy using viral vectors, base editing repairs the original mutation directly. As explained by Dr. Dr. Simon Krooss, a physician and scientist at the Department of Gastroenterology, modifying the mutated base creates a single-strand break on the opposite DNA strand. The target cell then automatically activates its natural internal repair machinery, incorporating the correct matching base into the second strand without triggering dangerous double-strand breaks. Following years of success in preclinical animal models, a joint clinical trial was initiated with Renji Hospital in Shanghai.
Seven patients who were sent to Shanghai accompanied by German medical personnel successfully underwent the experimental treatment. Among them was 55-year-old Katrin H., who was diagnosed at Medizinische Hochschule Hannover in 2011 and had suffered from progressive breathlessness for years. In March 2026, she received a single infusion of the novel base-editing drug. Subsequent follow-up testing demonstrated that her liver resumed producing functional alpha-1 antitrypsin without any reported adverse side effects, enabling her to stop weekly augmentation therapy completely.
Future Outlook and What the Discovery Means for International Patients
The successful treatment of these first seven patients marks a pivotal moment in gene therapy for inherited metabolic diseases. Although base editing cannot undo structural lung or liver damage that has already occurred prior to treatment, it can halt the disease process completely. For patients like Katrin H., this stabilization means preventing further organ deterioration and preserving overall quality of life.
To make this therapy widely accessible in Europe, Medizinische Hochschule Hannover plans to initiate clinical trials on site in early 2027. This expansion will eliminate the need for European and international patients to travel to Asia for clinical trial participation. Furthermore, Professor Ott emphasized that this revolutionary single-base replacement approach can eventually be adapted to treat numerous other congenital genetic disorders of the liver.
International patients seeking specialized care in Germany can consult with German hepatology and pulmonology experts to evaluate their eligibility for upcoming clinical trials. When speaking with German specialists, patients should ask about comprehensive genetic profiling, organ staging, and trial inclusion criteria. German university medical centers remain at the forefront of translating cutting-edge scientific discoveries into safe, effective clinical treatments for complex inherited diseases.
Source: Medizinische Hochschule Hannover