Barth Syndrome is named after the Dutch Paediatric Neurologist, MasaBarth.
The discovery of an X-linked mitochondrial disease affecting cardiacmuscle, skeletal muscle and neutrophil leucocytes was first mentioned in 1981but was then full described in 1983. In 1991, 3-methylglutaconic aciduria wasfound to be a clinical biochemical marker for Barth syndrome, G-CSF was thensuccessfully used to treat neutropenia in Barth Syndrome in 1995. (Barth Syndrome Foundation, 2016). According to the scientific article “OrphanetJournal of Rare Diseases” it states the Barth Syndrome was first describedin 1983 and it is widely regarded as a rare X-linked genetic diseasecharacterised by cardiomyopathy (CM), skeletal myopathy, growth delay,neutropenia and increased urinary excretion of 3-methylglutaconic acid (3-MGCA)(Clarke et al, 2013). “Barth syndrome affects multiple body systems and is diagnosed inmostly males.
Fewer than 200 living males are known worldwide to be living withthis syndrome, however, with more evidence that is being gathered it is obviousthat this disorder is substantially under diagnosed” (Clarke et al, 2013). In 1999, Cantlay et al had reportedthat there were five unrelated Barth Syndrome families identified from theSouth-West of England and South Wales. This statistic has greatly increasedover the past few years where the NHS Specialised Services Barth SyndromeService (NSSBSS) has so far identified a total of 30 unrelated families thathave been affected by the disease in the UK where 22 of these are boys or menare alive from 17 unrelated families. Barth syndrome has a very unique pathogenesis, it is the only knownhuman disease where the primary defect is remodelling of cardiolipin, aphospholipid found in mitochondrial membranes.
The syndrome affects many bodysystems from foetal through to adult life. Because of this wide range it makesit a very important condition of obstetricians, geneticists, generalpaediatricians, cardiologists and neurologists to be aware of, especially sincerapid definitive biochemical testing has recently become available. Barth Syndrome is usually passed from a carrier mother to her sonthrough a malfunctioning gene. This abnormal gene is carried on an X chromosome,the syndrome is inherited in an X-linked recessive manner from mother to son asmales that carry an X-linked disorder pass their abnormal gene onto theirdaughters and they then become the carriers of the abnormal gene. As femaleshave two X chromosomes they can usually block out the disease by ‘turning off’one of them but as males carry one X and one Y chromosome then of the maleinherits an X chromosome that has been turned off and has a non-working gene withinIt then there a huge possibility that he will develop this specific diseaseassociated with the non-working gene and this is the reason why Barth Syndromeoccurs majorly in males. The Genetic and Rare Diseases information Centre at the National Centrefor Advancing Translational Sciences states that “Barthsyndrome is caused by mutations in the TAZ gene, which is located on the Xchromosome. The TAZ gene provides “instructions” for a group ofproteins called tafazzins that serve at least two functions. First, theseproteins play a role in the maintenance of the inner membranes of structuresinside cells called mitochondria.
Cells depend on mitochondria to produce theenergy they need. Tafazzins are supposed to make sure that the concentration ofa specific fat (cardio-lipin) is sufficient to maintain energy productioninside the mitochondria. Tafazzins also promote the development of bone cells.Mutations in the TAZ gene that cause Barth syndrome disrupt the protein’sability to function correctly, thereby causing the signs and symptoms of Barthsyndrome.” (National Centre for Advancing Translational Sciences, 2011).There are a few different causes of Barth Syndrome that have beendiscovered over recent years.
In males suffering with Barth Syndrome one of themain symptoms is that dilated cardiomyopathy may be present at birth and if itis not present at birth and there are other symptoms then there is a goodchance that it may start to develop in the first few months of their life. Asthe person suffering from Barth Syndrome grows up and time goes on there is agood chance that their heart muscle will start to become weaker resulting inless blood being pumper around the body. As a result of a weakness in the heartthere is a possibility that some people may opt to have elastic fibres put inplace of their weakened muscle fibres within the part of the heart thatcontributes to the cardiomyopathy.Individuals suffering from Barth Syndrome may suffer from skeletalmyopathy, in particular of the muscles closest to the centre of the body, thisis usually very noticeable from birth and this causes hypotonia (low muscletone). Due to this muscle weakness it often causes a delay of the individual’smotor skills such as crawling and walking and they usually suffer from extremetiredness during strenuous physical activity. The majority of the males thatsuffer from this syndrome have neutropenia, this is where the levels of theirwhite blood cells can be consistently low (persistent) and they can vary fromnormal to low (intermittent) or they can cycle between regular episodes ofnormal and low (cyclical). Suffering from neutropenia makes it a lot moredifficult for the body to fight off the foreign invaders of the body such asbacteria and a number of viruses, this means that these affected individualshave an increased risk of recurring infections throughout their life.
As wellas having the symptoms listed previously, someone suffering from Barth Syndromeit is possible that the individual may have higher levels of 3-methylglutatonicacid in their urine or blood.There are a number of waysto check if an individual has Barth Syndrome. There are a number of differentmedical tests that may be carried out by a doctor to determine this, thesetests may include urine analysis and complete blood count. If the results fromthese tests indicate that the individual has this syndrome, then further testsand diagnosis will be confirmed with a DNA test.
Once an individual has beendiagnosed with Barth Syndrome other tests including an echocardiogram may becarried out to determine how severe the condition may be. The completediagnosis will then be made based on all the results gathered including medicaland family history information. There is also the option for pregnant woman toget a prenatal DNA test. Once an individual has been diagnosed with Barth Syndrome there are anumber of treatments they may partake in, however there is no cure or specifictreatment for this condition yet. Any treatment that may be given to anindividual is used solely to help and reduce the symptoms or to help preventany complications such as infections.
Below is a list of possible treatmentused to help treat Barth Syndrome; Ø PhysicalTherapy: This is used to help any babies that are affected who may have reducedmuscle tone.Ø Antibiotics:These are used to help prevent and treat bacterial infections.Ø Lifestylechanges: Doctors may suggest an individual to have a low-salt diet andmaintains a healthy weight.Ø HeartmedicationsØ ArtificialpacemakerØ Hearttransplant: This may be used in some severe cases if the individual’s conditionleads to cardiomyopathy to help prevent heart failure in the future. With suffering from Barth Syndrome there are a number of sacrifices thatan individual has to make throughout their life.
One of the main sacrificessomeone has to make is changes in their diet. As an individual grows up changeshappen that affects the body and their food choices. If suffering from thiscondition at a young age the individual has to stick to a strict diet but astheir teenage years come they have a lot more freedom to choose what they eat.However, it is still very important for the individual to eat foods that makethem feel good and healthy.
Their healthy diet is just the same as any otherteenagers, but many people find it a lot harder to stick to when suffering fromBarth Syndrome and if they make bad, unhealthy food choices it will affect howthe person feels. There are a number of tips that doctors may give someone that issuffering from Barth Syndrome to help them maintain a healthy diet. One ofthese main tips is to choose low GI carbohydrates, these foods are wholegrainfoods and are full of fibre so they fill the individual up for longer and takelonger to turn into fat. They are also advised to eat a protein in every mealsuch as chicken, turkey, milk, nuts or eggs but they are warned to stay awayfrom ones that have extra fat such as pies, pasties or battered food. Breakfastis a very important meal for someone who is suffering from Barth Syndrome adtheir body has used up all the stored energy overnight and if breakfast ismissed the body will start to use their muscles for energy is they have norefuelled.