Macrocephaly-developmental delay syndrome is a rare intellectual disability syndrome characterized by macrocephaly mild dysmorphic features (frontal bossing long face hooded eye lids with small downslanting palpebral fissures broad nasal bridge and prominent chin) global neurodevelopmental delay behavioral abnormalities (e.g. anxiety stereotyped movements) and absence or generalized tonic-clonic seizures. Additional features reported in some patients include craniosynostosis fifth finger clinodactyly recurrent pneumonia and hepatosplenomegaly.
Data from Orphanet are used to provide information on a disease's name, synonym(s), and overview. Reference: Access aggregated data from Orphanet at Orphadata. Orphadata: Free access data from Orphanet. © INSERM 1999. Available on http://www.orphadata.org. Data version July 2026
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Macrocephaly-developmental delay syndrome?
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Advocacy Organizations
PPP2CA Pathways
PPP2CA Pathways connects families, shares strength, and supports the research community in the search for answers to Houge-Janssens Syndrome type 3.
ReNU2 Foundation
ReNU2 Foundation fosters collaboration, supports families, raises awareness, and advances research into RNU2-2-related neurodevelopmental disease. We connect a growing global community of families, clinicians, and researchers spanning 19 countries, working urgently to ensure every family has access to testing, informed care, and treatments that will change lives.
ReNU2 United
ReNU2 United fosters collaboration, supports families, raises awareness, and advances research into RNU2-2-related neurodevelopmental disease.
Uganda Alliance of Patients Organization
Supporting patients to access quality, safe and patient-centered healthcare services.
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Clinical Trials
For a list of clinical trials in this disease area, please click here.