Towards a safety net for management of 22q11.2 deletion syndrome: guidelines for our times

The commonest autosomal deletion, 22q11.2 deletion syndrome (22q11DS) is a multisystem disorder varying greatly in severity and age of identification between affected individuals. Holistic care is best served by a multidisciplinary team, with an anticipatory approach. Priorities tend to change with age, from feeding difficulties, infections and surgery of congenital abnormalities particularly of the heart and velopharynx in infancy and early childhood to longer-term communication, learning, behavioural and mental health difficulties best served by evaluation at intervals to consider and initiate management. Regular monitoring of growth, endocrine status, haematological and immune function to enable early intervention helps in maintaining health.

CONCLUSION

Guidelines to best practice management of 22q11DS based on a literature review and consensus have been developed by a national group of professionals with consideration of the limitations of available medical and educational resources.

High Prevalence of Hearing Loss in Down Syndrome at First Year of Life

Introduction: Infants with Down syndrome (DS) are at higher risk of hearing loss (HL). Normal hearing at one year of age plays an important part in language development. An audit was conducted to determine the impact of the newborn hearing screening program on the incidence, type and timing of diagnosis of HL during first year of life. Materials and Methods: Infants with DS were scheduled for Universal Newborn Hearing Screening (UNHS) within 4 weeks of life. If they passed, they had a high-risk screen at 3 to 6 months. They were referred to the otolaryngology department if they did not pass the UNHS or the high-risk screen. Information was obtained from the computerised data tracking system and case notes. Infants born from April 2002 to January 2005 and referred to the DS clinic of our hospital were analysed. Results: Thirty-seven (82.2%) of 45 infants underwent UNHS, of which 12 (32.4%) infants did not pass. Of remaining 33 infants, 27 had high-risk screen done of which 14 (51.8%) did not pass. Twenty-eight infants were referred to the ear, nose, throat (ENT) clinic: 12 from UNHS, 14 from high-risk screens and 2 from the DS clinic. Eleven (39.2%) defaulted follow-up. Fourteen (82.3%) of 17 infants who attended the ENT Clinic had HL. Twelve (85.7%) were conductive, and 2 (14.2%) mixed. Nine (64.2%) had mild-moderate HL and 3 (21%) had severe HL. The mean age of diagnosis was 6.6±3.3 months. All were treated medically, plus surgically if indicated. By 12 months of age, the hearing had normalised in 4 (28.6%) infants and remained the same in 3 (21.4%). Five (35.7%) defaulted follow-up. Thirty-five out of 45 (77.8%) underwent complete hearing screen in the first year of life (UNHS & High-risk screen). Six out of 45 (13.3%) had incomplete screening. Fourteen out of 41 (34.1%) had HL of varying degrees. Four out of 45 (8.8%) did not have any audiological assessment in first year of life. Conclusion: The incidence of HL in the first year of life was high (34.1%). Eighty-five percent were conductive with 64.2% in mild-moderate range. One third of infants hearing normalized after treatment, one third remained unaltered and one third of infants did not attend follow-up. An aggressive approach involving early screening after birth and continued surveillance and early referral to appropriate agencies are essential for establishing timely diagnosis and treatment. Measures to reduce the high default rate during long-term follow-up are needed. Parent education and integrated multidisciplinary follow-up clinic may be useful. Key words: Deafness, Trisomy, UNHS

The impact of aging on eating, drinking, and swallowing function in people with Down's syndrome

Many people with Down's syndrome (DS) experience eating, drinking, and swallowing (EDS) difficulties, which can potentially lead to life-threatening conditions such as malnutrition, dehydration, and aspiration pneumonia. As the life expectancy of people with DS continues to improve, there is an increasing need to examine how the aging process may further affect these conditions. Published research studies have yet to address this issue; therefore, this article draws on the literature in three associated areas in order to consider the dysphagic problems that might develop in aging people with DS. The areas examined are EDS development in children and adolescents with DS, EDS changes associated with aging, and EDS changes associated with dementia of the Alzheimer's type (DAT) because this condition is prevalent in older adults with DS. This article concludes that unlike in the general population, the aging process is likely to cause dysphagic difficulties in people with DS as they get older. Therefore, it is suggested that longitudinal studies are needed to examine the specific aspects of EDS function that may be affected by aging and concomitant conditions in DS.

Thyroid dysfunction in Down's syndrome and screening for hypothyroidism in children and adolescents using capillary TSH measurement

Thyroid dysfunction is more common in individuals with Down's syndrome (DS) than in the general population, whose clinical features can mask the presenting signs and symptoms of hypothyroidism. Biochemical screening is necessary; however, venepuncture may be difficult.

AIMS

To assess the prevalence of thyroid dysfunction in children and adolescents with DS and the feasibility of screening for hypothyroidism using capillary dried blood spot thyroid stimulating hormone (TSH) from infancy.

METHODS

394 children (217 boys, 177 girls) were clinically assessed for thyroid dysfunction and 305 children (aged 4 months to 18.9 years) were screened for hypothyroidism by capillary whole blood TSH sample.

RESULTS

Thyroid dysfunction was detected in 4.6%, with 50% unscreened since neonatal screening. Parents reported minimal distress by fingerprick screening.

CONCLUSION

DS is associated with an increased prevalence of thyroid dysfunction, particularly in preschool children. Biochemical screening is essential and capillary whole blood TSH sampling for hypothyroidism is feasible, less invasive and acceptable.

Is there an association between functional bladder outlet obstruction and Down's syndrome?

OBJECTIVE

The incidence of urinary tract abnormalities in patients with Down's syndrome (DS) is estimated to be 3-7%. Abnormalities included are renal hypoplasia, renal cysts, ureterovesical and ureteropelvic junction obstruction and, more recently, an association between males with DS and the non-neurogenic neurogenic bladder has been reported. Based on clinical experience, the hypothesis is tested that patients with DS have functional bladder outflow obstruction secondary to detrusor sphincter dyssynergia.

METHODS

This study comprised three parts: an initial retrospective review of case notes of existing patients, followed by a prospective community-based study of all patients with DS to assess the incidence and types of bladder dysfunction, and a final hospital-based assessment where a problem was identified following return of the questionnaire.

RESULTS

The retrospective study identified a high potential for renal injury with three out of seven patients requiring urinary diversion for dilated upper tracts secondary to bladder outflow obstruction. The prospective study identified a high incidence (77%) of bladder dysfunction with 68% having a history of wetting.

CONCLUSION

There is a potentially serious problem in children with DS that is not widely appreciated. We recommend that, at the very least, such children have a detailed history of bladder function taken, and where a problem is detected a urinary tract ultrasound scan should be performed.

ENT and speech disorders in children with Down's syndrome: an overview of pathophysiology, clinical features, treatments, and current management

Down's syndrome is the most commonly occurring genetic abnormality, involving about 1 in 600 births. The increasing life expectancy of individuals with Down's syndrome has revealed the presence of several unexpected pathological processes. Among these, ENT disorders hold an important place because of their high incidence and severity. Accurate knowledge of the pathophysiology underlying ENT disorders (facial dysmorphism, ear abnormalities, upper airway abnormalities, and immunodeficiency) allow an understanding of the reasons for the development of the upper airway obstruction, obstructive sleep apnea syndrome, subglottic stenosis, deafness, speech delay, and ENT infections that occur frequently in these children. Early screening and specific treatment may allow some of the long-term sequelae to be avoided, or at least their prognosis to be improved. In order to help health care professionals in their daily practice, this review makes a series of recommendations to allow them to develop a master plan for the ENT management of children with Down's syndrome. In children with Down's syndrome, ENT disorders occur frequently and are often severe. They develop owing to craniofacial, functional, and immune system abnormalities. Early screening and treatment allow improvements in long-term outcomes.