Specialists for rare diseases (Orphan Diseases, Neurology & Dermatology)

    Clinical Teaching Practice of the Jewish University (JUC, United States)

  • Our Senior Specialists for Rare Diseases

    Neurology | Neuroimmunology | Endocrinology | General Practice

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    Prof. Dr. David Seideman


    Neurology, Neuroimmunology, Neuroendocrinology


    Professor Dr. David Seideman is an experienced neurologist, neuroimmunologist, and neuroendocrinologist who long served as a regular clinician in mid- and large-sized hospitals. Over time, Seideman became increasingly involved in Dr. Marius Lazar's team and eventually succeeded him as Director of Lazar, Seideman, Smith & Colleagues in the fall of 2022 as part of a thoughtfully scheduled generational transition.


    Dr. David Seideman is a professor at the Jewish University (JUC). As a rather small Messianic Jewish university, JUC does not operate a university hospital itself. In the case of clinical matters as well as research needs, the LCG Consortium and LCG Research as well as our international practice for rare diseases (Lazar | Seideman | Smith) proudly serve as teaching institutions for well-defined clinical aspects. The director and coordinator of this cooperative effort has been Prof. Dr. David Seideman since summer 2022. He is also still holding his lectures on the scientific study of consciousness. In addition, Professor Dr. Seideman is the Medical Director of the entire Lazar Medical Consortium Group (LCG).


    Even at a time when hardly anyone took the term "rare disease" seriously, Professor Seideman was already working on the treatment of precisely such conditions. The fact that he is working in uncharted medical territory every day does not unsettle him, but rather motivates him time and again.


    Throughout his career, he has been focussed fully on his work as a clinician, but has never lost touch with science. Being an approachable and compassionate teacher of the next generation of physicians, he is always personally available and concerned about every patient, every young colleague and every student.


    Professor Dr. Seideman is working hard on applying the standards and knowledge of evidence-based medicine (as much as possible) to the treatment of rare and under-researched diseases. We apologize that Professor Seideman currently has a waiting list of about eight months for consultations. Thoroughness is his standard, and that takes a lot of time.


    Frequently present in:

    Tel Aviv, Athens, Luxembourg, Madrid, Denver

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    Dr. Carolina Diamandis

    Vice Director

    Military Physician (ret.), GP/Internist

    • Personal advisor to Prof. Seideman
    • Care for long-term patients with rare diseases.
    • Head of LCG Research
    • Experience: Military Doctor, retired

    Frequently present in:

    Athens, Messenia and Nicosia

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    Dr. Lucas Smith

    2nd Vice Director

    Internist - Endocrinology

    As former director of Hellenic Health™ (dissolved after a merger) Dr. Smith has been working as a neurologist and endocrinologist (internist), specialized in orphan disease. Under Dr. Lazar he was the private assistant of Dr. Lazar. Now Dr. Smith is an esteemed senior physician with LSS, specialized internist and endocrinologist (orphan/rare/ultra-rare diseases) with a strong focus on the effects of neuropsychiatric syndromes on other organ systems. Appointments with Dr. Smith directly are available through the service center of the Lazar Group.


    Frequently present in:

    Athens, Nicosia, Luxembourg, Edinburgh

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    Dr. Jonathan Feldman

    Senior Specialist

    Internal Medicine and Dermatology

    • Emergency service for long-term patients with rare diseases.
    • Person to contact when the senior physicians are unavailable.
    • Experience: seasoned staff physician in several countries.

    Frequently present in:

    Tel Aviv, Athens, Nicosia, Bucharest, Dubai

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    Dr. Olga Ivanova

    Senior physician

    • General medicine (internist)
    • Decades of experience in eastern Europe
    • Former military physician

    Frequently present in:

    Bulgaria, Serbia, Romania, Moldova, Greece

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    Dr. Marius Lazar

    Founder | Partner

    Neurologist, Psychiatrist, Neurodermatologist


    For Dr. Marius Lazar, medicine is much more than just a job. As a neurologist, psychiatrist, dermatologist (immunodermatology) and, of course, general practitioner, he compassionately helps patients with rare diseases, worldwide. As native of Transylvanian Saxony, who lived for a long time in Africa as a diplomat's son, he practices in English and German.


    Due to the establishment of a steady and excellent medical team and the happy circumstance of a new marital bliss, Dr. Lazar has largely retired from the clinical field and, together with his wife, is devoting most of his energy to the Luzia Healthcare Society, which can enable free treatment for patients with rare diseases, wherever/ whenever possible. Nevertheless, Dr. Lazar continues to lend a hand whenever his expertise is needed at LSS.


    You can see him in person or via video consultations worldwide. Dr. Lazar offers the entire spectrum of diagnostic procedures of evidence based medicine in cooperation with local colleagues in the countries where his patients live. At the same time, Dr. Lazar is founder of the Lazar Medical Consortium Group, which provides medical networking worldwide.


    Here, in his private practice Dr. Lazar is specialized in rare neurologic diseases (orphan diseases) as well as difficult cases at the crossroads of dermatology and immunology. He takes a multidisciplinary approach to providing excellent, individualized patient-centered care by bringing together a collaborative care team with different perspectives. His patients have access to a team of specialists, the latest diagnostic methods, personalized treatments and the latest research.


    All of this on the basis of providing affordable help for everyone and at a strict distance to the pharmaceutical industry or any other lobby group.


    For people with orphan diseases, it can be difficult to understand their condition, the medical problems they may encounter, and the options for treating their symptoms. That's why Dr. Lazar relies on a network of specialists in the diagnosis and treatment of such diseases who share his ethical standards.


    Frequently present in:

    Athens, Bucharest, Pretoria

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    Dr. Simon Nathan

    Senior Physician | Head of the 24/7 service for LSS patients

    GP & Family Medicine

    • Together with Dr. Anna Schmidt-Christidis taking care of seriously ill LSS patients at nights, weekends, and public holidays
    • Experience: clinician in several hospitals of different size
    • 15 month focus training in telemedicine
    • Speaks several languages, among them English and German fluently

    Frequently present in:

    Judea & Samaria, Greece, Belgium, Luxembourg

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    Dr. Ali Asgari

    Senior Assistant

    GP | Specialist for off-label and innovative drug use

    • Head and manager of the 24/7 emergency service for long-term patients with rare diseases
    • Closely working together with Dr. Lazar
    • Experience: clinician in several large hospitals
    • Research assistant of Dr. Lazar

    Frequently present in:

    Romania, Luxembourg, Dubai, United Kingdom

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    Dr. Adrian Tudor

    External Partner

    Provides our 24/7 night standby with his partner team.

    • Family doctor
    • Public health and social medicine specialist
    • Specialized in diabetes care and blood pressure issues
    • Provides our 24/7 on-call coverage with his own team for the Lazar Medical Consortium Group (LCG) as a whole.

    Frequently present in:

    Bucharest, Hermannstadt, Sofia, Cyprus

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    Walter Seideman, MD

    Senior Physician. Head of the supervisory board

    As a senior physician and part of Seideman Medical Walter has a sharp eye on the quality standards of all units of the Lazar Consortium Group (LCG). LCG works with 189 doctors worldwide (and more than 3500 physidians when including our large international cooperation partners). All we do happens under the constant supervision of the non-profit Supervisory Board of the Lazar Medical Consortium Group, whose presidency has been taken over from Luzia Healthcare by Walter Seideman as of January 1st, 2023. Walter Seideman is an internist who has been working for the pharmaceutical industry for decades. He is a member of the large Seideman(n) family which has acquired the majority of LCG from Dr. Marius Lazar in 2022.

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    Alicia Popescu

    Chief assistant

    Phone +30 21 123447-27

    E-mail: administration@lazar-consortium.com

  • Together.

    Closer to you than you might think.

    As an international reference practice for rare diseases, we cannot have every patient come to Athens or even fly around the world ourselves. Therefore, we have excellent partners in countless countries. Look at the world map: in the colored nations, we have partner physicians and infrastructure at our disposal. For our patients this means short distances and the comforting feeling of being in safe hands.


    Our training facilities in cooperation with JUC: Athens, Luxembourg, Madrid, Bucharest, Pretoria 

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  • LCG Greece Research

    We share our experiences as clinicians of LSS with LCG

    and other non-profit research teams .

    Working with rare diseases means learning, an ongoing process.

    We share clinical observations as quickly as possible, bypassing lengthy academic discussions.

    Team Dr. Carolina Diamandis | Team Dr. David Seideman

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    We are proud EU-Europeans, dear friends of the United Kingdom, the Jewish nation, as well as blessed with close ties to the United States. In whatever we do, we try to represent the best the EU has to offer: compassion, innovation, and a little bit of a creative chaos.
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    We are a proud member of open AIRE (Open Access Infrastructure for Research in Europe) is a European initiative aimed at promoting open access to research outputs and facilitating the discovery and reuse of research information. It provides a platform for researchers, institutions, funders, and policy makers to discover and access the full text of research articles, datasets, and other research outputs, as well as information about projects, funding, and collaborations.


    OpenAIRE offers a variety of services and tools for researchers, including a discovery portal for accessing open access research outputs, support for data management and sharing, and integration with research information systems. The initiative also provides guidance and support for researchers and institutions to comply with open access mandates and funding requirements.


    OpenAIRE aims to make research outputs more discoverable and accessible, enabling researchers to build on the work of others and facilitate collaboration and innovation in research. It plays a key role in promoting open science and advancing the transition to a more open, collaborative, and transparent research ecosystem.


  • Medical examinations for telemedicine patients

    Possible thanks to our international partners.

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    Laboratory tests

    All state of the art laboratory tests are available in more than 30 countries.

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    MRI, CT, TCS

    Our partner practices and clinics perform examinations with MRI, CT and TCS (sonography of the brain). Scintigraphy is also still possible but less common than in the past. Due a three-step diagnostic procedure you will get an unusually high level of safety.

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    Neurological exams

    All standard neurological tests are being provided by carefully selected partners in over 50 countries.

  • The Doctor will see you now.

    Here you are taken seriously.

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    How Lazar | Seideman | Smith works

    Clear rules.


    Our top priority is to treat you as individually as your condition requires. Remote treatments (video telemedicine) in the strict sense are performed, but only in well-defined cases. Highly qualified colleagues in over 20 countries perform those physical examinations for us which are not possible via video conference and telemedicine.

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    Prudence, vigilance and diligence.

    Remain humble to what you don’t know.


    Since no one is omniscient, being well-networked makes a big difference. Dr. Lazar has always made it a point to network with as many colleagues as possible. After all, there's nothing worse than a doctor who thinks he knows everything. Therefore “better safe than sorry” is his credo.


    Dr. Lazar puts great emphasis on continuously educating himself and sharing his knowledge. That's why he also contributes pro bono as an editor to DocCheck's medical encyclopedia, among other projects.


    Diagnosing and treating rare diseases is more important than ever. Thousands of rare diseases exist, up to about seven thousand rare diseases have already been described scientifically, and more are being identified on an ongoing basis. Yet they remain mostly unknown in day-to-day medical practice. Medical and scientific knowledge about rare diseases is far from sufficient in the medical profession. The subject area of rare diseases has long been neglected by physicians, politicians and scientists, so that neither appropriate health policies nor scientific initiatives existed.


    For most rare diseases there is no efficient therapy, nevertheless appropriate interventions can improve the quality of life and also increase life expectancy. Some impressive progress has been made in the treatment of certain diseases, which should motivate us to intensify research efforts.


    Patients with rare diseases mostly face similar problems. Difficulties exist mainly in terms of diagnosis, availability of relevant information and referral to appropriate specialists. Equally important is access to qualified specialist facilities, general social and medical support, effective cooperation between hospitals and general practitioners, professional and social integration or maintaining independence.


    Those affected often face psychological, social, economic or cultural problems. Many patients do not receive a diagnosis because the lack of sufficient scientific and medical knowledge means that a rare disease is often not recognized. It is precisely this group of patients that is exposed to the greatest pressure of suffering, as they are denied access to adequate support.

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    We are first and foremost human beings.

    And care about our patients, more than usual.


    Those with a rare disease who are patients of Lazar, Seideman & Smith see their attending specialist every 10 to 14 days. In addition, a team of assistant physicians with a variety of specialties is available 24 hours a day for our long-term patients. Those who receive their treatment under the Luzia Healthcare u.n.a. social program are not billed for treatment by our assistant doctors. Or, to put it briefly: we take good care of our patients.

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    Rare diseases are a challenge

    What we are confronted with.


    Orphan diseases, also known as rare diseases, are defined as conditions that affect fewer than 200,000 people in the United States. There are over 7,000 rare diseases affecting approximately 400 million people worldwide. Diagnosis and treatment of rare diseases face several challenges, including:


    • Lack of Awareness: As the name suggests, these diseases are “rare” and as such, there is often limited awareness and understanding of these conditions among the general public and even healthcare professionals. This can lead to misdiagnosis and delayed treatment.
    • Limited Research and Development: Due to the small patient population and limited financial incentives, there is often limited research and development into orphan diseases. This can lead to a lack of knowledge about the underlying mechanisms and treatments for these conditions.
    • Lack of Diagnostic Tools: There is often a lack of diagnostic tools and tests for rare diseases, leading to difficulties in accurately diagnosing the condition.
    • Difficulty in Finding Specialists: There may be only a few healthcare professionals who specialize in a particular rare disease, making it difficult for patients to access specialized care and treatment.

    In conclusion, the low prevalence of orphan diseases makes it challenging to diagnose and treat them effectively. The limited research and development, lack of diagnostic tools, and difficulty in finding specialists all contribute to the difficulties faced in diagnosing and treating these conditions.


    That's the reason why we do what we do.

  • Our social responsibility

    Everyone should have access to the best possible care.

    Social fee system

    The diagnosis and treatment of rare diseases is complex and requires ongoing consultations between all the physicians involved. Therefore, high costs are a consequence of this process. In order to cushion these effects, we have a fee system that is graduated according to the financial strength of the patients. In this solidarity system, wealthy and well-insured patients enable the treatment of less well-off patients in a mixed calculation.

  • Contact us

    In case of an emergency, please call an ambulance immediately!

    EU administration
    16 Kifissias Ave, 115 26 Athens
    Hellenic Republic
    10:00h - 18:00h (local time)
    +30 21 123447-27
  • Information 

    Videos (from inspiring colleagues)

    What is neurology?

    Why the world needs neurologists.

    International exchange.

    A key factor for a high quality standard.

    Dr. Josep Dalmau

    Neurology Journal

    PsychScene Hub

    Dr. Sanil Rege

    Treating, learning, teaching.

    That’s what we do.

  • Independence

    and other principles that are important to us.

    Our international practice for rare neurological diseases always strives to incorporate all the latest research findings directly into the diagnostic process and the treatment of our patients. In doing so, we are guided by the following values, without any exception:



    We do not use third-party funds, are not part of unnecessary professional associations, and do not maintain relations with representatives of the pharmaceutical industry.



    We have all our analog and digital infrastructure regularly audited by the relevant specialists.



    All our international partner practitioners are regularly audited in terms of equipment, quality and patient ratings.

  • We are a teaching practice

    for the Jewish University (JUC, United States)

    Teaching Practice of the Jewish University (JUC, United States)


    As a the teaching practices of Faculty III (Medical and Health Sciences) of the Jewish University (JUC, CO, United States), we bring together evidence-based and strictly science-oriented medicine with the values of Messianic Judaism. But what is meant by this? Of course, not religious practices, but a worldview on humanity that guides us. Just as is the case with the clinics run by Christian churches in Europe. In terms of the students, there is a focus on teaching internships for students of health sciences. Especially when working with patients suffering from rare diseases, one is at the intersection of established scientific knowledge, medical art ("sophisticated trial and error"), as well as a profound human component. For students of a faith-based university, this field is like a burning glass where various layers of life converge.

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    Teaching locations


    The Jewish University (JUC, CO, U.S.A.) is not only the world's only higher Messianic Jewish educational institution, but as a now enduring response to the Sars-2 pandemic, it is also a globally active web-based university. As a similarly structured teaching practice for Faculty III (Medical and Health Science) some aspects of education require reliable venues that are readily accessible to all students.


    Globally training facilities are currently located in:

    • Athens (Dr. Makris, Dr. Smith, Dr. Diamandis, Dr. Balaskas, Prof. Dr. Seideman)
    • Pretoria (Dr. Lazar)
    • Tel Aviv (Prof. Dr. Seideman, Prof. Dr. Gangnon)
    • Bucharest (Prof. Dr. Gangnon)
    • Madrid (Prof. Dr. Seideman)
    • Luxembourg (Prof. Dr. Seideman, Prof. Dr. Gangnon, Dr. Smith, et al.)
    • Denver (Prof. Dr. Seideman)

    Would you believe that this young man is seriously ill? Yes, neither does he. That's why one of the focal points of our work is iron metabolism disorders, which are so much more than just classic hereditary hemochromatosis. We are also quite active in and for the H63D Syndrome Research Consortium.

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    Wir helfen auch auf Deutsch.



    Dr. Lazar, Prof. Dr. Seideman und Dr. Smith haben jeweils eine teils sehr enge Bindung an Deutschland bzw. die deutsche Sprache, so dass das Deutsche eine von mehreren Arbeitssprachen unseres Teams ist. Natürlich pflegen wir auch enge Kontakte zu ärztlichen Kollegen in Deutschland und in Österreich, um eine gute Versorgung dieser Patienten am Wohnort sicherstellen zu können.


    Zögern Sie daher nicht, uns auch auf Deutsch anzusprechen. In unserem kleinen Sekretariat in Luxemburg (für Nord- und Westeuropa) ist Deutsch die hauptsächliche Verkehrssprache.



    +352 2033424-5



    • Internationales Team, das Wissen aus verschiedenen Ländern und Institutionen zusammenführt.
    • Cross-border (immer dort, wo die passenden Diagnostiker sind) State-of-the-art Diagnostik. Behandlung und Forschung im Bereich der sehr seltenen Orphan Diseases in den Bereichen Neurologie, Neuropsychiatrie, Neuroimmunologie und Psychiatrie.
    • Verbindung von Video-Medizin mit klassischen Arztbesuchen vor Ort bei kooperierenden Kliniken und Praxen.
    • Arzt-Patienten Konsultation mit unseren Spezialisten mindestens alle 14 bis 30 Tage.
    • Konsiliarische Begleitung von Behandlungen, wenn die eigenen Plätze belegt sind, um keinen Patienten mit einer seltenen Erkrankung alleine zu lassen.
    • 24/7 Rufbereitschaft unserer zahlreichen, internationalen und sorgsam ausgewählten Assistenzärzte.
    • Je nach Krankheitsbild bis zu täglichen Online-Visiten unserer Assistenzärzte.
    • Enge Zusammenarbeit mit den lokalen Kollegen am Wohnort des Patienten.
  • Get well soon.

    Life. More healthy.

  • Unser “Senior” Team

    International, engagiert und dem Menschen zugewandt.

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    Dr. Marius Lazar

    Neurologe & Psychiater


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    Prof. Seideman


    Teaching Professor (JUC)

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    Dr. Lucas Smith




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    Dr. C. Diamandis

    Ehem. Militärärztin

    Leiterin der LCG Research


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    Dr. S. Nathan

    Allgemein- und Familienmedizin



  • Wir bleiben an Ihrer Seite.

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    Selbstverständlich kann eine weltweit vernetzte Praxis nicht mit nur drei oder vier Chefärzten alle Patienten versorgen. Wir als Lazar, Seideman & Smith haben daher neben unseren weltweiten Partnerpraxen auch direkt von uns beauftragte Assistenzärzte, die ein unverzichtbarer Teil von Lazar, Seideman & Smith sind. Als pars pro toto seien genannt:


    Dr. Sofia Makri

    Dr. Olga Ivanova

    Dr. Evi Papadopoulou

    Ms. Natalia Nikolaidi

    Dr. Benjamin Steinberg

    Dr. Alexander Papadakis

    Dr. Maria Mitsotaki

    Dr. Anna Schmidt-Christidis

    Dr. Simon Nathan (Leitung)


    …und viele mehr


    Wir tun alles in uns Mögliche dafür, dass dieses Team möglichst stabil ist und bleibt. Denn wir arbeiten nur mit Kollegen, denen wir voll und ganz vertrauen - fachlich wie auch menschlich. Unsere Patienten haben daher idealerweise stets ein vertrautes Behandlungsteam.

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    • Neurologische Krankheiten führen, sehr viel häufiger als viele Laien es sich vorstellen, zur Notwendigkeit einer Verordnung von Hilfsmitteln. 
    • Krücken, Rollstühle, Gehhilfen, Orthesen und so genannte Schutzhelme machen dabei die Mehrheit der Apparaturen aus, die oft die Lebensqualität und Mobilität verbessern.
    • In den deutschsprachigen Ländern gehört die Verordnung von Hilfsmitteln in die Hände unserer lokalen Partnerpraxen, damit die Kassen die Kosten übernehmen können.
    • Allerdings bieten wir allen Patienten unseres internationalen Praxisnetzwerks zusätzlich die Beratung durch unseren sehr erfahrenen Orthopädietechniker an, um in Ruhe die Notwendigkeit eines Hilfsmittels feststellen zu können und auch dessen Anwendung zu begleiten. 
    • Oft ist die Compliance aufgrund von Scham leider recht niedrig. Auch in diesen Situationen begleitet unter Techniker und das Team der Assistenzärzte die Patienten durch den Weg in die Gewöhnung an ein neues Hilfsmittel.
  • Legal & Privacy

    and other useful information.