Williams syndrome and growth hormone deficiency

Growth, body composition, and endocrine issues in Williams syndrome

PURPOSE OF REVIEW

Williams syndrome is a multisystem disorder caused by a microdeletion on chromosome 7q. Throughout infancy, childhood, and adulthood, abnormalities in body composition and in multiple endocrine axes may arise for individuals with Williams syndrome. This review describes the current literature regarding growth, body composition, and endocrine issues in Williams syndrome with recommendations for surveillance and management by the endocrinologist, geneticist, or primary care physician.

RECENT FINDINGS

In addition to known abnormalities in stature, calcium metabolism, and thyroid function, individuals with Williams syndrome are increasingly recognized to have low bone mineral density, increased body fat, and decreased muscle mass. Furthermore, recent literature identifies a high prevalence of diabetes and obesity starting in adolescence, and, less commonly, a lipedema phenotype in both male and female individuals. Understanding of the mechanisms by which haploinsufficiency of genes in the Williams syndrome-deleted region contributes to the multisystem phenotype of Williams syndrome continues to evolve.

SUMMARY

Multiple abnormalities in growth, body composition, and endocrine axes may manifest in individuals with Williams syndrome. Individuals with Williams syndrome should have routine surveillance for these issues in either the primary care setting or by an endocrinologist or geneticist.

Endocrine manifestations in children with Williams-Beuren syndrome

AIM

Endocrine abnormalities in Williams-Beuren syndrome (WBS) include growth retardation, precocious puberty, hypercalcaemia and thyroid disorders. We aimed to characterise these abnormalities in a national cohort of children with WBS.

METHODS

A retrospective study comprising a national cohort of individuals with WBS in Israel (16 males, 18 females) followed between 2010 and 2016.

RESULTS

The age at diagnosis of WBS was 1.4 ± 1.0 years. Height standard deviation score (SDS) at last visit was correlated with the midparental height SDS (r = 0.46 p = 0.007). Yet, participants did not reach their midparental height, with a difference of 1.40 ± 0.85SD (p < 0.001). Short stature below the 3rd percentile was found in 14 participants (41%). Mean insulin-like growth factor 1 SDS was low (-0.61 ± 1.64) and was correlated with the mean height SDS (r = 0.63 p = 0.038). Two participants were diagnosed with growth hormone deficiency, and initiation of growth hormone treatment improved their height velocity. A total of eight participants (23.5%) had mild hypercalcaemia, five girls (14.7%) had precocious puberty and five participants (14.7%) had thyroid abnormalities.

CONCLUSION

Individuals with WBS had a distinct growth pattern consisting of growth restriction at all ages, resulting in final adult height in the low-normal range. Precocious puberty, hypercalcaemia and thyroid abnormalities should be screened for and treated as needed.

Clinical expression of familial Williams-Beuren syndrome in a Turkish family

Williams-Beuren syndrome (WBS) is a rare genetic disorder characterized by distinctive facial features, intellectual disability with a typical neurobehavioral profile, cardiovascular anomalies, and occasional infantile hypercalcemia. Majority of cases occur sporadically, and only a few cases of familial WBS have been reported. Although pre- and post-natal growth retardation is a common clinical feature of the syndrome, growth hormone deficiency is detected only in a few patients. To our knowledge, there has only been one report about familial Williams-Beuren syndrome in the Turkish population. Here, we report on the three molecular cytogenetically confirmed familial Williams-Beuren syndromes detected in a family with familial short stature. The father, daughter, and son analyzed with clinical and laboratory findings, and reasons of the short stature in Williams-Beuren syndrome are discussed through the literature.

New height, weight and head circumference charts for British children with Williams syndrome

AIM

To produce a growth reference for British children with Williams syndrome.

METHODS

The children and adults recruited into the study were all affiliated to the Williams Syndrome Foundation, a parent support group founded in 1979. They have all been shown to have a deletion of chromosome 7q11.23. One growth nurse (WRS) prospectively measured the weight, height and head circumference of individuals from 19 regions in Great Britain including Scotland, England and Wales. 169 children and adults were measured on up to four occasions between 2001 and 2004 (275 measurements). In addition, retrospective data were obtained from the hospital notes of 67 of these individuals (586 measurements). Centile curves were constructed using Cole's LMS method.

RESULTS

The centile charts differ from charts previously derived in the USA and Germany and provide more appropriate standards for the British population.

CONCLUSIONS

We propose that these charts be adopted for routine clinical practice as abnormalities in growth are an important feature of this syndrome.

Williams syndrome and related disorders

Three clinical conditions displaying phenotypic overlap have been linked to mutation or deletion of the elastin gene at 7q11.23. Supravalvar aortic stenosis, an autosomal dominant disorder characterized by elastin arteriopathy, is caused by mutation or intragenic deletions of ELN resulting in loss of function. Autosomal dominant cutis laxa, a primarily cutaneous condition, is the result of frameshift mutations at ELN that cause a dominant-negative effect on elastic fiber structure. Williams syndrome, a neurodevelopmental disorder is due to a 1.5 Mb deletion that includes ELN and at least 15 contiguous genes. The disorder is characterized by dysmorphic facies, mental retardation or learning difficulties, elastin arteriopathy, a unique cognitive profile of relative strength in auditory rote memory and language and extreme weakness in visuospatial constructive cognition, and a typical personality that includes overfriendliness, anxiety, and attention problems. The understanding of these disorders has progressed from phenotypic description to identification of causative mutations and insight into pathogenetic mechanisms for some aspects of the phenotype.

Growth hormone deficiency in the Rothmund-Thomson syndrome

We describe the first proven occurrence of growth hormone deficiency in an individual with the Rothmund-Thomson syndrome. This was suspected because of the patient's severely retarded growth and bone age and her failure to respond normally to growth hormone stimulation testing with l-DOPA, arginine, and growth hormone releasing factor. In addition, we have briefly reviewed other genetic and malformation syndromes that have been found associated with growth hormone deficiency. We recommend that growth hormone deficiency be considered in these syndromes, especially when the growth failure is more marked than expected.