Tetrasomy X

Definition

Tetrasomy X is a sex chromosome anomaly caused by the presence of two extra X chromosomes in females (48,XXXX instead of 46,XX).

Also known as 48,XXXX syndrome, quadruple X, tetra X, tetrasomy type X — per MONDO

Also identified as

• ICD9 758.81 per MONDO
• MESH C536502 per MONDO
• Orphanet 9 per MONDO
• SCTID 10567003 per MONDO
• UMLS C0265496 per MONDO