25- down's syndrome

Down syndrome, also known as Trisomy 21 due to the presence of a third twenty-first chromosome, is one of the most common and well known birth anomalies. One in every 650 children born will be effected by this syndrome.

Characteristics
Some of the facial features which identify an individual as having Down syndrome include:

• Low set ears
• Up slanting palpebral fissures
• Low nasal bridge and dorsum
• Abnormal and excessive facial fat distribution
• Protruding, enlarged tongue

Frequency of Dysmorphic Signs in Neonates with Trisomy 21

Dysmorphic sign Frequency (%) Flat facial profile 90 Poor Moro reflex 85 Hypotonia 80 Hyperflexibility of large joints 80 Loose skin on back of neck 80 Slanted palpebral fissures 80 Dysmorphic pelvis on radiographs 70 Small round ears 60 Hypoplasia of small finger, middle phalanx 60 Single palmar crease 45

trisomy 21 - down syndrome , trisomy 18 - edwards syndrome , trisomy 13 - patau syndrome