What is Poikiloderma Congenitale (Rothmund-Thomson Syndrome)?
Congenital poikiloderma, also known as Rothmund-Thomson syndrome (RTS), is a rare genetic skin disorder, inherited in an ‘autosomal recessive’ manner (which means both parents must carry and pass on a copy of the defective gene). This disorder is usually noticeable from an early age and is known for causing reddish skin patches
(poikiloderma) on the face, along with a range of other symptoms. These may include being shorter than the average height, having thin scalp hair or missing eyelashes or eyebrows, early-onset cataracts, bone deformities, early aging, and a higher chance of developing a type of bone cancer called osteosarcoma.
Rothmund-Thomson syndrome comes in two varieties. Type 1 usually results in quickly progressing, bilateral (i.e., affecting both eyes), juvenile cataracts. On the other hand, type 2 is characterized by abnormalities in the bones from birth, and an increased risk of developing osteosarcoma during childhood and squamous cell carcinoma (a type of skin cancer) at an older age.
What Causes Poikiloderma Congenitale (Rothmund-Thomson Syndrome)?
The specific gene responsible for type 1 RTS, a certain genetic disorder, hasn’t been discovered yet. On the other hand, type 2 RTS is caused by certain specific changes or mutations in a gene called RECQL4. This is found in about 60% to 65% of patients with type 2 RTS.
The RECQL4 gene belongs to a family of genes known as RecQ-helicases. It is located on a part of the 8th chromosome that is labeled as 8q24.3. This gene is responsible for making a protein, the RecQ DNA helicase, which plays a crucial role in the process of DNA duplication and repair.
Risk Factors and Frequency for Poikiloderma Congenitale (Rothmund-Thomson Syndrome)
Congenital poikiloderma is a rare condition, with around 300 cases reported in medical literature. Almost two-thirds of these cases are of a type known as type 2 RTS. This condition can be inherited, but most reports involve individual cases rather than multiple people in the same family. Interestingly, the overall number of males and females with this condition is about the same, although some reports show that one gender may be more affected than the other. Importantly, congenital poikiloderma affects all ethnic groups.
- About 300 cases of congenital poikiloderma have been reported in medical studies.
- Almost two-thirds of these cases are of type 2 RTS.
- Most cases of this inherited condition are isolated incidents, with only some cases involving multiple family members.
- The number of males and females affected is generally equal, but there may be a gender imbalance in some instances.
- Congenital poikiloderma can affect individuals of any ethnicity.
Signs and Symptoms of Poikiloderma Congenitale (Rothmund-Thomson Syndrome)
Congenital poikiloderma is a condition typically diagnosed by a dermatologist, based on its impact on the skin, hair, nails, and teeth. It can also affect other body parts, but this is less common and happens later.
The skin symptoms start showing between the 3rd and 6th month of a baby’s life, beginning with redness of the cheeks. This rash can spread to the arms and legs, and possibly even the buttocks. The stomach and chest areas are usually spared. If the redness is intense, puffiness and blisters can appear. Over time, this progresses to spot-like skin thinning with changes in skin color and appearance of tiny, permanently dilated blood vessels, creating the typical look of poikiloderma.
Further skin features of the syndrome can include café-au-lait spots (patches of skin that appear light brown), signs of early skin aging, and skin overgrowths on the hands and feet. Many patients have sparse, thin, or absent hair on their scalp, eyebrows, or eyelashes. It’s also common to see changes in the nails, such as dystrophy (abnormal growth) or pachyonychia (thickened nails), and dental problems, including small or undeveloped teeth, odd tooth shapes, and a high occurrence of cavities.
Eyes can be affected too, with cataracts being the most common problem. They develop mostly in the early years and can cause blindness. Other eye conditions might include corneal thinning, bulging eyes, congenital glaucoma, retina thinning, squint, sensitivity to light, and blue-tinged whites of the eyes.
Skeletal abnormalities show up in about 68% of patients and include a sunken nose, prominent forehead, and abnormalities in the long bones. Additionally, the syndrome can lead to systemic issues, such as slow growth, low birth weight, short stature, mental retardation, hearing loss due to nerve damage, digestive issues like a narrow entrance to the stomach or a blocked anal canal, dilated small airways in the lungs leading to frequent lower respiratory tract infections, low white blood cell counts, and chronic mild anemia.
The most significant risk with congenital poikiloderma is the potential for development of cancer, which can be life-threatening. The most common cancers associated with this syndrome are bone (30%) and skin (5%) cancers. Osteosarcoma, a type of bone cancer, has the same characteristics as sporadic bone but starts earlier (age 14 compared to 17).
In some cases, there can be multiple osteosarcomas, which is more common than expected with sporadic osteosarcoma. The most common skin cancer is squamous cell carcinoma. Other rare reported cancers in these patients are basal cell carcinoma, Bowen disease, melanoma, blood cancers (myelodysplasia, Hodgkin’s and non-Hodgkin’s lymphomas, acute myeloid leukemia) and visceral cancers (fibrosarcoma, stomach cancer).
Testing for Poikiloderma Congenitale (Rothmund-Thomson Syndrome)
Examining skin lesions under a microscope (a process known as histological examination) is usually not needed. This approach doesn’t often provide much useful information for diagnosis. Instead, it’s more important to have systematic x-rays or other forms of imaging to check for any abnormalities in bones, as these might not be noticeable during a physical examination. Your doctor will use your medical history and the results of your physical exam to decide what other tests (biological and radiological) may be needed.
Treatment Options for Poikiloderma Congenitale (Rothmund-Thomson Syndrome)
Congenital poikiloderma is a condition that requires regular check-ups by a team of medical experts, which often includes a skin doctor (dermatologist), an eye doctor (ophthalmologist), a cancer specialist (oncologist), and a bone doctor (orthopedic surgeon). These check-ups should happen at least twice a year to catch any changes, like changes in the skin, the development of a cataract (clouding in the eye lens), or a bone tumor. Treatment focuses primarily on preventing issues before they occur.
This precautionary approach may involve careful protection from sunlight. Tips for good sun protection include wearing long-sleeve shirts, using sunscreen with a high protection level, and trying to avoid excessive sun exposure.
Any visible red spots or small, dilated blood vessels (telangiectasias) on the skin’s surface can be treated with a specific type of laser treatment called pulsed dye laser therapy.
Cataracts would need surgical treatment. And if bone tumors are found, the orthopedic surgeon and the oncologist would work together to manage them.
Aside from these, other issues associated with congenital poikiloderma, like dental or respiratory abnormalities, may also need early and specialized care.
What else can Poikiloderma Congenitale (Rothmund-Thomson Syndrome) be?
The identification of congenital poikiloderma, a genetic skin condition, isn’t always straightforward. There are several others that share similar symptoms and thus, could be mistaken for it. These include:
- Bloom syndrome
- Werner syndrome
- Cockayne syndrome
- Xeroderma pigmentosum
- Fanconi anemia
It’s important to note that the abbreviation AR, labeled next to some conditions, means that these conditions are autosomal recessive. This means they are inherited, coming from both parents’ genes.
What to expect with Poikiloderma Congenitale (Rothmund-Thomson Syndrome)
The outcome can vary greatly. People without cancer can expect to live a normal lifespan. However, for those with cancer, their condition largely depends on how often they get screened for cancer and the kind of treatment they receive.
People with a condition called type 2 RTS should have regular check-ups because they’re more likely to develop cancer. The treatment plan usually includes using a laser to treat small visible blood vessels, going for an eye exam every year, and having imaging tests to check for bone pain, difficulty walking, or fractures that could indicate a bone cancer called osteosarcoma.
It’s also been observed that there might be an increased sensitivity to the side effects of chemotherapy in these patients, and that they have a 5% risk of developing skin cancer.
Possible Complications When Diagnosed with Poikiloderma Congenitale (Rothmund-Thomson Syndrome)
The main issue with RTS, or Rothmund-Thomson Syndrome, is that it makes people more prone to cancer.
Preventing Poikiloderma Congenitale (Rothmund-Thomson Syndrome)
People who have a condition called congenital poikiloderma should know that getting a lot of sun can raise their chance of getting skin cancer. So, it’s really important to protect yourself from the sun. This can include staying in the shade as much as possible, wearing clothes that cover up your skin, and using sunscreens that protect against all types of harmful sun rays. Another problem they might face is losing their sight due to the development of cataracts. Family members might want to consider genetic counseling, as this condition can be inherited.
