What the micro deletion 22q11.2 or Di George's syndrome?

 

 

 

Also known under the name of Syndrome Vélo-Cardio-Facial: VCFS in the Anglo-Saxon countries. By the Doctor Yves ALEMBIK, Service of genetics of the FALLEN of Strasbourg and the Professor Stephan ÉLIEZ of the Service of Guidance Infantile of FALLEN Geneva

In each of our cells, there are 23 pairs of chromosomes numbered from 1 to 22, the last one were the one sexual chromosomes X and Y which are going to determine the male genital organ ( X Y ) or the female genital organ ( X X ) Every initial cell consists to equal parts of paternal and maternal genetic heritage(holdings). Every chromosome possesses a called long arm "q" and an arm runs(roams) called "p", these arms are gathered(combined) between them by the Centro mere. A micro-deletion is the loss of a small segment of chromosome understanding(including) several genes.

From 1965, the Doctor DI George describes for the first time the symptoms observed at four children in the birth: cardiac abnormality associated with an abnormality of thymus, and a hypocalcaemia by abnormality of parathyroid.

In 1978, the Doctor SHPRINTZEN describes a particular aspect of the face associated with a Palatine crack, with an abnormality of the larynx. Furthermore, these children presented confusions of the learning. This syndrome carries(wears) the name of syndrome Vélo-Cardio-Facial or VCFS or still syndrome of Shprintzen.

In 1981, the Doctor OF THE CHAPEL thinks of a genetic abnormality. He(it) discovers that the symptom is associated with the Chromosome 22. 10 years later, in 1991, the Doctor Driscol will show the systematic existence of a micro deletion of the chromosome 22 detectable thanks to the genetic markers ( FISH)... A geneticist was known well the Doctor Mr. Michael Cohen, Jr., often said that the geneticists were more inclined to share their toothbrush than their terminology.

For different reasons, the VCFS is known under a certain number of naming, among others Di George's sequence, syndrome of Shprintzen, cardio facial syndrome of Cayler, syndrome of the deletion 22q, the syndrome of the conotroncales abnormalities and the face (Japan) and inconveniently the CATCH22.

©  2008  à  2010     Tout droits réservés      Fondation Amanda Raymond-Lamoureux pour le syndrome de Di George

The CATCH22 can be certainly crossed off from the list of the acceptable naming because it is a tasteless funny attempt (making reference to the short story(piece of news) and black comedy JOSEPH HELLER'S CATCH22). The naming of "Di George" was given after the Doctor Angelo Di George, the endocrinologist of the Hospital St - Christopher in Philadelphia, described the athymie  ( Absence of thymus) and the hypoparathyroïdisme to a certain number of newborn children. We know since, that some of them had the VCFS. Di George's sequence is so appointed because it represents a set of symptoms of aetiology non-specific and the causes of which can be multiple. For example, the athymie and the hypoparathyroïdisme were found at child's suffering from the syndrome of foetal alcoolisation, the syndrome of Nikawa-Kuroki and the chromosome rearrangements others than the chromosome 22. Di George's sequence is present at a small number of infants with the VCFS, but the majority do not have it.

 

The VCFS is too little known and nevertheless, he appears recently in the pantheon of the syndromes and he exists typically a gap enters a first publication on a new disorder (978 for the VCFS) and its wide acceptance within the medical profession. Of more the VCFS draw less the attention than the disorders as the Down's Syndrome (Trisomy 21), Because the children affected by the VCFS are not so much stigmatized physically and because their syndrome can pass unnoticed during several years, given that the diagnosis is difficult, in particular at the infants. We can however be delighted at the recent growth of interest for the VCFS and the remarkable progress in its study and its gratitude(recognition) during the last 5-6 years.

The symptoms which we observe mostly are:

  • Abnormalities of the palace and the ears:

    imperative to set up a very premature guidance orthophonique (from 1 year), sometimes a surgical operation to facilitate the language The presence to 95 % of the persons affected by a Palatine crack, sometimes under mucous membrane, of a too short palate or an abnormality of the throat can entail difficulties of language preventing a good understanding of the child. It will be and of this fact the schooling.

     After the age from 5 to 7 years, all the taken care children speak, where from the necessity of a premature diagnosis and an immediate care in partnership with the parents. The ear infections are frequent and can end in the long run in an additive loss if they are not correctly handled. A installation of a drain(s) in the ear(s)  is often necessary.  The ear infections result from an immunizing deficit but especially deformations of the pharynx. An abnormality of the internal ear can also alter the hearing and will be to look for.

    • Appetite problems:

     Strictly connected to the abnormalities of the throat or the larynx.

    •  Cardiac deformations:

    Connected to an infringement of parathyroid glands which can pull(entail) crises of tetanus to the quite small and personality problems at the child as well as delay of growth and dysfunction of the colonist: an appropriate treatment can mitigate these so necessary problems, and a regular surveillance will be organized.

    •  Trouble of the immune systems:

    An absence or a bad development of the thymus can entail an important reduction of cells of the immune system of type lymphocyte T. Infections very frequent ENT in 78 % of the cases at the child can again aggravate the difficulties of pronunciation or hearing. Adapted antibiotic treatments improve considerably the everyday life, especially in the first years.

    • Deformations of the urinary system:

    The absence of a kidney is frequent. Although it generally has no consequences at the child, it is important to know it because this information is going to lead the doctor to the choice of certain medicines and to treat strongly any urinary infection.

    • Constipation:

    One or several causes of which are known still very badly. The hypocalcaemia seems to be one of disrupting(perturbing) elements but doubtless not the only one. These problems show themselves grave in 32 % of the cases.

    • Hormones problems:

    Deficits of the thyroid gland and parathyroid were brought back(reported). It is important for the regular doctor to be informed about this problem because it is not still evident to detect these deficits at children. The hypocalcaemia (reduction of the rate of blood calcium), indicated by crises of tetanus, is one of consequences of the hypo parathyroid.                                                                                                                                                                 

    • Scoliosis:

    Very frequent: 42 % of the cases, it requires a care of physiotherapy and a constant surveillance. A follow-up by an orthopedist who will propose soles from the youngest age seems to have a beneficial effect on the development of the scoliosis.

    • Mobility(motricity)  problems:

    70 % of the cases A care in psychomotricity is necessary to improve the fine motricity and the persevering spatiotemporal difficulties.

    • Hypotony:

    Present in 95 % of the cases, it entails a slight delay of the psychomotor development and a certain gesture slowness: a premature and continuous re-education and the assistance of the parents will ease the effects.

    • Delay in the learning and the deficit of attention:

    Present in almost all the cases, 98 % of the cases, it is the major challenge with which the parents are confronted. In the micro-deletion 22q11 are very often associated the confusions of the cognition and the learning. More the diagnosis will be premature, better will be the care. The role of the parents is essential in the future of the child. It is thanks to their support, their presence, their constant, attentive, patient requests and without faults that the child will progress. As in many genetic abnormalities, the glance of the professionals changes. Indeed, the more the number of diagnosed families increases, the more the variations appear. Till the beginning of the 90s, only the gravest cases were known. Today, with the progress of the knowledge of the syndrome, we put in evidence that 78 % of the affected children could follow a "normal" schooling until third, with a support very so parental as medical. It remains to convince the teachers to accept our children in the classes.

    • Psychiatric and schizophrenia problems: 

    To 20 to 25 % of the adults, we were able to observe psychiatric confusions. One of the difficulties in the investigation of the psychiatric confusions at the child or the teenager is that their severity evolves with the age, becoming typically more severe at the adult.

    These various symptoms can find solutions. It is however important not to treat them separately some of the others, because he can have important interactions there. The relatives have to be actively involved in every case in the various re-educations of the child. The knowledge of this genetic abnormality is still incomplete. Its complexity, the involvement of a large number of genes and thus the very numerous symptoms which result from it ( 185 observed), return the difficult research.

    It is from the sharing of the information, from the exchange between professionals, and associations that appear research ideas, and, in the case of the micro deletion 22q11.2, the congresses are of a major importance to make progress the knowledge and thus the care of the patients and the research on this syndrome.

     

     To know more about The Disease: Di George's syndrome