{"id":2761,"date":"2023-05-18T14:22:43","date_gmt":"2023-05-18T12:22:43","guid":{"rendered":"https:\/\/ern-ithaca.eu\/?page_id=2761"},"modified":"2026-04-02T16:54:11","modified_gmt":"2026-04-02T14:54:11","slug":"phelan-mcdermid-guideline","status":"publish","type":"page","link":"https:\/\/ern-ithaca.eu\/it\/guidelines\/ern-ithaca-guidelines\/phelan-mcdermid-guideline\/","title":{"rendered":"Phelan-McDermid Guideline"},"content":{"rendered":"

Introduction to the <\/a>European Consensus Guideline for Phelan-McDermid syndrome<\/h2>\n\n\n\n
<\/div>\n\n\n\n

Phelan-McDermid syndrome (PMS) (OMIM#606232) is a neurodevelopmental disorder caused by a deletion 22q13.3 a pathogenic variant in the gene SHANK3<\/em> that is located at 22q13.3.<\/p>\n\n\n\n

In 2020, the Guidelines working group of the European Reference Network ITHACA (I<\/strong>disabilit\u00e0 intellettiva, T<\/strong>eleHealth, A<\/strong>autismo e C<\/strong>non congenito A<\/strong>nomalies) established an international consortium of professional and lived experience experts representing 14 European countries (see Consortium<\/a>), in order to update and adapt an already existing Dutch guideline to the European situation.<\/p>\n\n\n\n

<\/div>\n\n\n\n

Aim of the guideline<\/h3>\n\n\n\n

The aim of the guideline is to provide recommendations for resolving the bottlenecks experienced in practice and to achieve more uniform and better-coordinated care for individuals with Phelan-McDermid syndrome. Patient representatives were involved in the selection of topics  and participated in writing the guideline. The recommendations are based on a careful weighing of the latest scientific insights and expert opinion. The guideline supports clinical decision-making and primarily targets those healthcare professionals involved in the care of children and adults with PMS, while also providing transparency to patients, parents and caregivers.  A short practical version of the guideline (Clinical synopsis<\/a>), a clinical surveillance scheme<\/a> e emergency card<\/a> and a lay version<\/a> in different European languages have been made as well.<\/p>\n\n\n\n

<\/div>\n\n\n\n

What does the guideline cover?<\/h3>\n\n\n\n

This guideline addresses issues for individuals diagnosed with Phelan-McDermid syndrome (PMS), due to a deletion 22q13.3 or a pathogenic variant in the SHANK3<\/em> gene. For the deletions, we specifically focus on deletions including SHANK3. <\/em>This can be terminal or interstitial deletions and also includes deletions caused by unbalanced translocations or a ring chromosome 22. For clarity and because the majority of the data is available for genetic abnormalities affecting the SHANK3<\/em> gene, we focus on individuals with a SHANK3 <\/em>haploinsufficiency (functional copy number loss), i.e. PMS SHANK3<\/em>-related. Nonetheless parts of this guideline may be applied to deletions 22q13 not <\/em>including SHANK3, i.e. <\/em>PMS SHANK3<\/em>-unrelated.<\/em><\/p>\n\n\n\n

<\/div>\n\n\n\n

Methods<\/a><\/h3>\n\n\n\n

A survey exploring the most important topics and needs experienced by parents was developed and made available online in different languages (English, French, Spanish, Portuguese, Dutch, German, Italian, Hungarian, Lithuanian, Swedish). Links to the survey were distributed among parents with the help of patient organisations. The survey was completed anonymously by the parents of almost 600 patients world-wide. The results can be found qui<\/a>.<\/p>\n\n\n\n

The guideline is based on the AGREE II instrument (Appraisal of Guidelines for Research & Evaluation II), which is an internationally accepted instrument and considered the most useful instrument to use in guideline development for rare disorders. After identification of the most important questions that needed to be addressed by the guideline, an extensive literature search was performed as described in the respective papers.<\/p>\n\n\n\n

Each chapter of the guideline was critically reviewed by the consortium members, including the patient representatives. The final text was discussed in detail with all consortium members during a consensus meeting in June 2022 in Groningen, Netherlands, and the recommendations were rephrased until consensus was met. A voting process allowed each member to vote regarding the reliability of each recommendation.<\/p>\n\n\n\n

<\/div>\n\n\n\n

Overview of topics of the European consensus guideline<\/h3>\n\n\n\n

For background information and the consensus recommendations we refer to the respective papers that have been published in the European Journal of Medical Genetics<\/a> . The following topics have been addressed:<\/p>\n\n\n\n