Down’s syndrome:  This is the most common of the chromosome abnormality syndromes typified by a wide range of abnormalities.  Otolaryngologic findings are numerous in these patients and can affect every region of the head and neck.  This includes small ears with overfolding of the superior helix, stenotic EAC and eustachian tube dysfunction.  There is also an increased incidence of chronic ear disease in affected children due to increased incidence of upper respiratory infections, reduction of B and T cell function (immune system immaturity), and eustachian tube dysfunction.  The hearing loss in DS is usually conductive secondary to the chronic middle ear disease but can also be due to ossicular chain abnormalities, especially the stapes.  Upper airway obstruction and OSA are also problems encountered by children with DS due to the midface hypoplasia, and relative enlargement of the tongue, tonsils and adenoids in a constricted naso/oropharynx.  Other systems affected include cardiovascular (ventricular-septal defect, tetrology of Fallot, patent ductus arteriosis), genitourinary (micropenis, low testosterone, infertility), musculoskeletal (atlanto-axial instability, short metacarpals and phalanges) and ocular (speckled iris; Brushfield spots).  In terms of speech and behavior, most Down’s syndrome patients exhibit dysarthria and articulation deficits in conjunction with some degree of mental retardation (IQ 30-50).