A human DNA sequence consists of 23 pairs of chromosomes. Each pair of chromosomes is further made up of for normal genetic growth and development. When the sequence has too many or is missing one or more chromosomes, or if a gene mutates, the information process becomes interrupted. This lack of or extra information causes a genetic disorder or syndrome. Such errors sometime lead to abnormal growth and development involving speech, language, and hearing. This comprehensive reference guide assists students, teachers, and practitioners in the applied health sciences field by providing general diagnostic and management guidelines. While not a comprehensive review of all existing genetic syndromes involving communication disorders, it is a concise text highlighting the syndromes commonly seen in interdisciplinary clinics (e.g., Downs Syndrome, Huntington's Disease, or Oto-Palatal-Digital, etc.) Chapters: 1.Principles of Medical genetics 2.Chromosomal syndromes 3.Single Gene Syndrome (Autosomal Dominant, Autosomal Recessive, and X-Linked Diseases) 4.Polygenic-Multifactorial syndromes 5.Non-Syndromic Hearing Loss 6.Sporadic syndromes 7.Environmental syndromes. Also included are (a) a glossary of genetic and medical terms, (b) a cross-reference index of syndromes by physical abnormality, and (c) Illustrations detailing specific characteristic dysmorphology of syndromes.