Newborn period. Hypotonia is the most striking characteristic, as well as typical dysmorphic features: small ears, broad thumbs and down slanting palpebral fissures. The child may develop drinking problems, which can be a sign of a CHD. In a child with a congenital defect of the gastrointestinal tract or cataract DS should be considered.

Heart defects. The prevalence of CHD in neonates with DS is about 44–58% worldwide. Atrioventricular septal defect and ventricular septal defect are the most common forms of CHD, constituting up to 54% for ASD and to 33% for VSD, of all CHDs in children with DS. A normal neonatal examination in children with DS does not exclude a serious CHD. Because of the high incidence of significant CHD in children with Down syndrome, early recognition of CHD is necessary as it can lead to the optimal management of the defect and can sometimes.

Respiratory problems are responsible for the majority of the morbidity and hospital admissions in children with DS. Respiratory syncytial virus (RSV) is seen more frequently and is associated with a greater risk for hospitalization in children with DS.  Recurrent wheeze is very common among children with DS.

Gastrointestinal tract disorders. Congenital defects of the gastrointestinal tract are present in 4–10% of children with DS and play an important role in morbidity during the first year of life. These defects include oesophageal atresia/ trachea-oesophageal fistula, pyloric stenosis, duodenal stenosis/atresia, Hirschsprung disease and anal stenosis/atresia. Coeliac disease (CD) is another DS specific disorder and is seen in 5–7% of children with DS. Screening for early detection of CD in the DS population, with the aim of starting treatment and preventing complications from untreated CD such as failure to thrive, anaemia, osteoporosis and malignancy, should be considered.

Endocrine disorders Thyroid disorders have been reported in up to 28–40% of children with DS, and they increase in frequency, up to 54%, as the children age. Thyroid abnormalities in children with DS range from congenital hypothyroidism to primary hypothyroidism, autoimmune (Hashimoto) thyroiditis and compensated hypothyroidism. Hyperthyroidism (Graves’ disease) occurs in children with DS as well.

Haemato-oncological and immunological disorders. Newborns with DS may have thrombocytopenia and polycythaemia. Children with DS have an increased risk of developing both acute myeloid as well as lymphoblastic leukaemia. Myeloid leukaemia in children with DS may be preceded by a preleukaemic clone (transient myeloproliferative disorder, TMD). TMD presents in 10% of children with DS. Transient leukaemia can subsequently develop myeloid leukaemia, usually with an onset before the age of 5.

Eye disorders include strabismus, nystagmus, congenital or acquired cataract, blepharitis, refractive errors and glaucoma. Keratoconus is rare in childhood but develops later in life in individuals with DS. Visual screening is essential for detecting defects that can be treated.

Ear, nose and throat disorders. Children with DS have recurrent upper respiratory tract infections. Mid-face problems, together with hypotonia and macroglossia (children with DS have a relatively large tongue compared to the oral cavity), are responsible for chronic middle ear disease and chronic rhinorrhea. Assessment of the hearing function in DS is recommended.

Orthopaedic disorders The motoric system of children with DS is characterized by ligamentous laxity and joint hypermobility. Cranio-cervical instability has been associated with DS as well as atlantoaxial instability (AAI). Usually, the AAI is an asymptomatic disease, symptoms may relate to an accident. There are limitations regarding both obtaining and interpreting and screening X-rays for AAI, and these are not predictive for injury. The performance of yearly neurologic screening is advisable, as is taking extra care when intubation is necessary. A specific gait, with external rotation of the hips, knees in flexion and valgus, and externally rotated tibias is associated with DS. In childhood, pes plano valgus is often seen, and in cases where marked pronation of the foot creates problems with stable ambulation, active support is recommended. Acquired hip dislocation, patellofemoral instability and slipped capital femoral epiphysis is seen more often in children with DS. An arthropathy similar to juvenile rheumatoid arthritis can develop in children with DS. The delay in motor development in children with DS is more pronounced than the delay in mental development. Physiotherapy may be supportive.

Urinary tract disorders Children with DS have significantly more risk of urinary tract anomalies. Symptoms may be masked because voiding disturbances and delayed toilet training.

Sexual development. In adolescent girls with DS, the onset of puberty is similar to that of other adolescents. In boys with DS, the primary and secondary sexual characteristics and pituitary and testicular hormone concentrations are similar to those in typical adolescents. Females with DS are able to have children, but males with DS have a diminished capacity to reproduce.

Dermatologic diseases are often present such as Alopecia areata, vitiligo, seborrhoeic eczema, folliculitis and syringoma are more frequently seen in children with DS. Rare but DS-specific problems are elastosis perforans serpiginosa and milia-like idiopathic calcinosis cutis.

Neuro-behavioural disorders Most children with DS function in the low range of typical development. In adolescence, cognitive function may reach a plateau that persists in adulthood. Counterproductive behaviour and avoidance tactics can impede learning, and language production is often substantially impaired. Delayed verbal short-term memory and expressive language indicate the need for a special approach to teaching these children to speak (for example, learning to speak by first learning to read). Furthermore, impaired oral motor function can influence articulation. Children with DS have more pronounced neurobehavioural and psychiatric problems. Epilepsy is seen in 8% of children with DS, with 40% occurring in infancy and often presenting as infantile spasms. Alzheimer’s disease which is associated with DS appears later in life, not in childhood.

Children with DS have several DS-specific morbidities and screening programmes are available to support and educate patients and their families.

This is a summary of the publication  M.E. Weijerman, J.P. de Winter. Clinical Practice. The care for children with Down syndrome. Eur J Pediatr (2010) 169:1445–1452 DOI 10.1007/s00431-010-1253-0