Date: October 10, 2011
NIH undiagnosed diseases programme documents two-year pilot
as clinic of last resort
Bethesda, Maryland. After its first two years of work, the Undiagnosed
Diseases Programme (UDP) of the National Institutes of Health (NIH) is
citing successes in patients whose cases have stumped specialists at
leading medical institutions around the country. The researchers
published the programmes first retrospective analysis in the September
26, 2011 early online issue of Genetics in Medicine.
The successes include the diagnoses of siblings whose calcium-riddled
blood vessels made it excruciatingly painful to walk, a woman with
life-threatening protein deposits in her muscles and a 20-year-old
whose diagnosis makes him the oldest survivor of his previously
undiagnosed muscle and lung disorder.
'The UDP responds to a critical unmet need, with compassion, clinical expertise and state of the art genomic technologies,' said Daniel Kastner, MD, PhD, scientific director at the National Human Genome Research Institute (NHGRI). 'A patient who cannot be diagnosed may cycle through the medical system with no satisfactory treatment plan or be abandoned by the medical system. Through the UDP, NIH provides a glimmer of hope to patients and their families, while at the same time gaining remarkable medical insights.'
The UDP is supported by the NIH Office of the Director, NHGRI, the NIH
Office of Rare Diseases Research (ORDR) and the NIH Clinical Centre.
The report focuses on 160 patients of the total 326 cases accepted
into the program. More than half of the accepted patients had
undiagnosed neurological problems. Other prominent disorder categories
include gastrointestinal disease; fibromyalgia and chronic fatigue
syndrome; immune-mediated and rheumatic illnesses; psychiatric
conditions; pain; dermatologic disorders; and cardiovascular disease.
So far, most of the solved cases - 37 of 39 cases for which the UDP
team arrived at a diagnosis - involved diseases previously encountered
in the world of medicine, according to UDP authors. In general, about 500 diseases are common enough to be in any physician's repertoire for diagnosis, while another 6,500 are known but are exceptionally rare, according to ORDR data.
UDP researchers reviewed, evaluated and diagnosed 23 patients with
rare diseases, of which 15 cases reflect extremely rare diseases
affecting fewer than 10,000 people. The authors note that while these
are known disorders, some lack diagnostic tests or medical definitions
to describe them. Rare diseases are defined as those affecting fewer
than 200,000 people in the United States.
The programme has also delved into the realm of unknown maladies. In
February, the UDP announced the programmes first discovery of a new
disease, called ACDC, or arterial calcification due to deficiency of
CD73, in the New England Journal of Medicine. CD73 is a protein that
produces a small molecule, adenosine, which protects arteries from
calcifying. A report on one additional new disorder is pending
The siblings whose cases led to discovery of ACDC continue to
experience pain while walking more than a short distance. The NIH
researchers, however, have obtained approval to start a drug treatment
protocol that could improve their condition, which will be initiated
The patient who UDP researchers encountered with an unexplained muscle
condition was diagnosed with a rare form of amyloidosis, a condition
in which bone marrow produces excess immunoglobulin proteins, which
had accumulated in the patient's muscle tissue. The NIH team referred
the patient for a stem-cell, bone marrow transplant, using healthy
donor stem cells. The patient has subsequently experienced progressive
improvement in her condition.
The UDP team also succeeded in diagnosing the 20-year-old patient with
a condition called spinal muscular atrophy with respiratory distress.
The condition causes damage to muscles, including respiratory muscles.
The patient remains dependent on a respirator for much of his day but
last year achieved the significant personal milestone of high school
graduation. The diagnosis has allayed the patient's concern that the
condition might at any point impair his learning.
A typical UDP patient visits the NIH Clinical Center for one week. The
case is evaluated by specialists from several of NIH?s 27 institutes
and centres, with expertise in areas such as neurology, radiology,
dentistry and rheumatology. A key component of the programme is
genetics, so researchers collect DNA from blood or tissue samples from
all participating patients, and often from family members to support
the genomic analyses.
Most of the patients accepted in the first two years of the UDP had
their DNA analysed for known single nucleotide polymorphisms (SNPs),
which reflect differences in the single chemical subunits of DNA that
could indicate a genetic disorder. Their tool in the SNP analysis
process is called a million-SNP array, which can be used to find
potentially important differences between the genome of an affected
individual and an unaffected family member, pointing to the genetic
cause of a disorder. This approach resulted in three successful
The researchers performed both whole-genome sequencing, deciphering
all of an individual's DNA code, and whole-exome sequencing, an
approach that decodes the 1-2 percent of the genome that contains
protein-coding genes. They analysed DNA from 32 patients, along with
DNA from 78 unaffected family members. This approach proved critical
for the diagnoses of six patients' disorders.
NIH is evaluating use of these advanced genomic analyses for broader
utility. The UDP diagnostic successes have proven the usefulness of
SNP detection techniques and genome sequencing tools - both whole
genome and whole exome sequencing - in the clinical evaluation of
patients, according to the study. But UDP researchers also know that
genome sequencing does not provide the whole answer. In addition to
genomic analyses, clinical findings - from specialty consults to
radiological tests - led to one third of the 39 diagnoses, according
to the study.
Doctors from around the country responded to the May 2008 call for UDP
applications, summarizing, documenting and sending the UDP 1,191 cases
for review within the subsequent two years alone. Each application
includes a referring health care provider summary letter and complete
'The applications may represent years of evaluation by multiple
doctors at more than one medical facility - but with no conclusive
diagnosis,' said William Gahl, MD, PhD, NHGRI clinical director and
UDP director. 'We look for some clue in the medical record - from an
abnormal lab test to a collection of symptoms that don't usually occur
together. If we can establish a direction for further follow up, we
may invite that patient to be seen by our team at NIH.'
NIH clinicians participating in UDP - up to 60 health care providers
at the nation's largest research hospital - screen the applications
and accept patients based on the availability of clinical and research
resources. The program currently has a backlog of applications and
since July 2011 has suspended acceptance of new applications until
'In addition to our discovery of new disorders, the UDP work has
expanded the clinical description - or phenotype - of numerous
disorders,' Dr Gahl said. 'The limited rate of diagnosis during the
programme is sobering. While we wish we could arrive at a conclusive
diagnosis for each patient, the reality is that many of their
conditions are likely new diseases and we continue to pursue clues
long after patients depart the hospital here at NIH.' To increase the
success rates, the UDP plans to make case descriptions available to
designated expert researchers, to both validate findings and enhance
understanding of disorders.
NHGRI is one of the 27 institutes and centres at the NIH, an agency of
the Department of Health and Human Services. The NHGRI Division of
Intramural Research develops and implements technology to understand,
diagnose and treat genomic and genetic diseases.
The NIH Clinical Centre (CC) is the clinical research hospital for the
National Institutes of Health. Through clinical research,
physician-investigators translate laboratory discoveries into better
treatments, therapies and interventions to improve the nation's health.
The NIH Office of Rare Diseases Research stimulates and coordinates
research on rare diseases and supports research to respond to the
needs of patients, healthcare providers and the research communities
involved in the care, treatment, and evaluation of products for the
prevention, diagnosis, or treatment of these conditions.
The Office of the Director, the central office at NIH, is responsible
for setting policy for NIH, which includes 27 Institutes and Centres.
This involves planning, managing, and coordinating the programs and
activities of all NIH components. The Office of the Director also
includes program offices which are responsible for stimulating
specific areas of research throughout NIH.
NIH, the primary federal agency conducting and supporting basic,
clinical, and translational medical research, and is investigating the
causes, treatments, and cures for both common and rare diseases.
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