Stromme Syndrome: Symptoms, Causes, and Treatments

Have you ever heard of Stromme Syndrome? It is a very rare, autosomal (appearing on non-sex chromosomes) genetic condition. and recessive (implying that both genes in a pair must be mutated to produce the disease).

This syndrome mainly affects the intestine, but also many other structures and systems (cardiac, skeletal, neurological...).

In this article we will know its most relevant characteristics, its symptoms, causes and possible treatments to apply.

• Related article: "Top 10 Genetic Disorders and Diseases"

What is Stromme Syndrome?

Stromme syndrome (in English, Strømme syndrome) is an autosomal recessive genetic syndrome, considered rare, that mainly affects the intestine. It produces intestinal atresia, which entails certain congenital malformations in the structure of the intestine (such as the lack of a part of it), which causes intestinal obstruction.

In the case of Stromme Syndrome, intestinal atresia is characterized by being "apple-skinned", which means that the remaining intestine is twisted around its main artery.

In addition to these malformations in the intestine, in Stromme Syndrome two other key symptoms also appear: ocular abnormalities and microcephaly.

Let us remember that the microcephaly it is a medical condition that implies that the brain does not develop properly in the baby, so the head is smaller than normal; microcephaly can appear at birth, or develop during the first years of life.

In Stromme Syndrome, the front third of the eye (also called the anterior segment or socket interior), which encompasses certain structures of the eye (cornea, iris, ciliary and lens body) is underdeveloped. In addition, the syndrome is characterized by a moderate delay in development.

These are the most typical symptoms of Stromme Syndrome, although others also appear, a little less frequently. One of them is interatrial communication (also called ASD), which consists of a congenital heart disease where blood flows between the atria of the heart.

In addition, in people with Stromme Syndrome, muscle tone is increased, and skeletal abnormalities often appear as well. Sometimes other conditions appear, such as intellectual disability, poor speech, poor motor function or other symptoms.

prevalence

Stromme's Syndrome it is a very rare condition, although its prevalence data is still unknown. It is known, yes, that in 2017 approximately 13 people were diagnosed with it.

Origin

They were Petter Strømme, a Norwegian pediatrician, along with his team, who identified the symptoms of Stromme Syndrome for the first time, in 1993 (as we can see, its name derives from its "discoverer").

Strømme and his collaborators observed the symptoms of the syndrome in two brothers, although it was not until 2008 that the syndrome was named for the first time, in a study with another patient. Later, in 2015, it was possible to accurately identify the pathogenic mutations produced in the CENPF gene, which characterize Stromme Syndrome.

Just one year after that date, in 2016, it was discovered, in the siblings who had manifested the symptoms in 1993, mutations in the CENPF gene (in both copies of the gene), through a genetic study. This is how these mutations in the gene could be identified as the cause of Stromme Syndrome.

• You may be interested in: "The 15 most important chromosome syndromes"

Symptoms

We have seen in a generic way what are the most characteristic symptoms of Stromme Syndrome; We are going to see them now one by one and in more detail.

1. intestinal atresia

The intestinal atresia that characterizes Stromme Syndrome consists of the absence of certain parts of the intestine, or the narrowing of the same. This implies an intestinal obstruction, which requires an operation.

2. ocular abnormalities

The eyes are usually smaller than normal, as well as being underdeveloped (also, this is usually seen more in one eye than in the other).

The alterations that can appear are: coloboma in the iris (a kind of hole), cataracts, sclerocornea (the cornea blends with the white of the eye), leucoma (clouding of the cornea), microcornea (cornea small)...

3. microcephaly

As we have already seen, microcephaly implies that the brain develops abnormally, which implies a smaller head than usual. Associated with it may also appear intellectual disability, seizures, dwarfism, motor disorders...

4. Moderate developmental delay

Generally, the delay in development is usually moderate to severe, although there are cases where it is mild.

5. atrial communication

The heart can also be affected in Stromme Syndrome, through heart disease congenital called atrial septal defect, which involves blood flowing between the atria from the heart.

6. Increased muscle tone

Also called hypertonia, increased muscle tone is another sign of Stromme Syndrome.

7. Skeletal abnormalities

The skeletal system is also altered through various abnormalities, such as: hip dysplasia (which can lead to dislocation), metopic craniosynostosis, flattened vertebrae, malformations in the thoracic wall (what is called sternal cleft), etc.

8. Physical characteristics (phenotype)

On a physical level (that is, in terms of phenotype), people with Stromme Syndrome They are usually short people, with large, low-set ears, a large mouth, and a small jaw., fine or sparse hair and epicanthic folds (which are folds of the skin of the upper eyelid, which cover the inner corner of the eye).

Causes

As we have seen, Stromme Syndrome consists of a genetic condition. It is caused by a series of mutations in both copies of a gene called CENPF; Said gene codes for the F protein of the centromere, which is involved in cell division processes.

On the other hand, the CENPF gene is linked to processes of cell division, migration and differentiation. What happens when this gene is mutated (mutations appear in it)? That cell division is slower, and also, certain processes of embryonic development are interrupted or incomplete.

How is Stromme Syndrome diagnosed? Generally, a clinical diagnosis is made, that is, based on the symptoms, although logically the Genetic tests are the ones that will confirm the diagnosis, in addition to providing much more information. complete.

Treatment

As for the treatment of Stromme Syndrome, it focuses above all on the symptoms (each of them will need its specific treatment). At the level of the intestine, and to treat intestinal atresia, what is done is to correct the malformation surgically, usually in childhood.

Specifically, a surgical anastomosis is performed, a technique used to incorporate a new connection between two fluid-carrying structures in the body (in this case, the intestines).

Forecast

As for the prognosis of this syndrome, it is still unclear. Most people with Stromme Syndrome survive to birth and infancy., although there is a part of the cases (a minority), which are more serious and do not survive (or die before birth, or shortly after).

Bibliographic references:

• Dorum, B.A., Şambel, I.T., Özkan, H., Kırıştıoğlu, I., Köksal, N. (2017). Stromme syndrome: new clinical features. APSP Journal of Case Reports. 8 (2): 14.
• Filges, I., Bruder, E., Brandal, K., Meier, S., Undlien, DE, Waage, TR, Hoesli, I., Schubach, M., de Beer, T., Sheng, Y., Hoeller, S., Schulzke, S., Rosby, O., Miny, P., Tercanli, S., Oppedal, T., Meyer, P., Selmer, KK, Stromme, P. (2016). Stromme syndrome is a ciliary disorder caused by mutations in CENPF. Hum. Mutat, 37: 359-363.
• Filges, I., Stromme, P. (2019). CUGC for Stromme syndrome and CENPF-related disorders. European Journal of Human Genetics: 1–5.
• Slee, J., Goldblatt, J. (1996). Additional evidence of an 'apple peel' syndrome of intestinal atresia, ocular abnormalities, and microcephaly. clin. Genet, 50: 260-262.
• Strømme, P., Dahl, E., Flage, T., Stene-Johansen, H. (1993). Apple peel intestinal atresia in siblings with ocular abnormalities and microcephaly. Clinical Genetics. 44 (4): 208–210.