syndromic intellectual disability syndromic disease sex chromosome disorder of sex development 49,XXXXY syndrome https://github.com/monarch-initiative/mondo/issues/6878 https://rarediseases.info.nih.gov/diseases/5679/49xxxxy-syndrome https://www.malacards.org/card/49xxxxy_syndrome ICD9:758.81 The 49,XXXXY syndrome represents a chromosomal anomaly of the aneuploidic type characterized by the presence of three extra X chromosomes in males. 49,XXXXY GARD:0005679 Orphanet:96264 XXXXY syndrome SCTID:38847009 MEDGEN:75573 NCIT:C185635 UMLS:C0265499 MONDO:0019929 chromosome X disorder pentasomy