Syndromes & Conditions - Trisomy
Birth defects - trisomy disorders -- Victoria: Better Health Channel 
Provides a brief overview of birth defects involving chromosomes. Three syndromes involving chromosomes (Down, Edward and Patau)are discussed and their characteristics explained. Risk factors during conception, diagnosis and where to get help are included.
The Chromosome 18 Registry and Research Society -- San Antonio, Tex.: The Chromosome 18 Registry and Research Society 
Provides information about various CH18 conditions and links to further resources.
Chromosome 22 central : support for Chromosome 22 related disorders -- Fuquay-Varina, NC: Chromosome 22 Central 
Supporting families who are directly or indirectly affected by 22C deletion, this site provides information on current research, upcoming events and conferences, resources on genetic disorders, personal stories from families affected by chromosomal disorders, chat rooms and discussion lists.
Patau Syndrome -- London: Contact a Family 
A brief overview of Patau Syndrome (Trisomy 13) including coverage of inheritance patterns and pre-natal diagnosis.
SOFT Australia : Support Organisation for Trisomy SOFT Australia 
A support network for families with children affected by Trisomy 18, 13 and other chromosonal disorders. This site provides introductory information on Trisomy and its newsletters are available on-line. It also provides contact details for SOFT organisations, Australian and international, as well as links to other relevant organisations and sites of interest.
Trisomy 9 website -- Perth: 2007.
A website by a Perth mother of a boy with Trisomy 9, this site provides information on the condition, a personal journal, and links to support groups and other relevant organisations.