Marilee A. Martens

Organ transplantation, organ donation and mental retardation

Abstract:  We reviewed the literature on accessibility and outcomes of organ transplantation in individuals with mental retardation (MR) and on the prevalence of organ donation in this population. Six centers have published outcome data on renal transplantation in 34 individuals with MR. The one‐ and three‐yr patient survival rates were 100% and 90%, respectively. The studies reported good compliance with post‐transplant medications due to consistent support from family members or caregivers. The outcome studies for liver and heart transplantation among these individuals are limited. The literature on organ donation in individuals with MR is mostly concerned with legal issues. The courts generally permit organ donations when such is in the best interests of the donor.

Continuous cognitive dynamics of the evaluation of trustworthiness in Williams syndrome

The decision to approach or avoid an unfamiliar person is based in part on one’s evaluation of facial expressions. Individuals with Williams syndrome (WS) are characterized in part by an excessive desire to approach people, but they display deficits in identifying facial emotional expressions. Likert-scale ratings are generally used to examine approachability ratings in WS, but these measures only capture an individual’s final approach/avoid decision. The present study expands on previous research by utilizing mouse-tracking methodology to visually display the nature of approachability decisions via the motor movement of a computer mouse. We recorded mouse movement trajectories while participants chose to approach or avoid computer-generated faces that varied in terms of trustworthiness. We recruited 30 individuals with WS and 30 chronological age-matched controls (mean age = 20 years). Each participant performed 80 trials (20 trials each of four face types: mildly and extremely trustworthy; mildly and extremely untrustworthy). We found that individuals with WS were significantly more likely than controls to choose to approach untrustworthy faces. In addition, WS participants considered approaching untrustworthy faces significantly more than controls, as evidenced by their larger maximum deviation, before eventually choosing to avoid the face. Both the WS and control participants were able to discriminate between mild and extreme degrees of trustworthiness and were more likely to make correct approachability decisions as they grew older. These findings increase our understanding of the cognitive processing that underlies approachability decisions in individuals with WS.

Auditory cortical volumes and musical ability in Williams syndrome.

Individuals with Williams syndrome (WS) have been shown to have atypical morphology in the auditory cortex, an area associated with aspects of musicality. Some individuals with WS have demonstrated specific musical abilities, despite intellectual delays. Primary auditory cortex and planum temporale volumes were manually segmented in 25 individuals with WS and 25 control participants, and the participants also underwent testing of musical abilities. Left and right planum temporale volumes were significantly larger in the participants with WS than in controls, with no significant difference noted between groups in planum temporale asymmetry or primary auditory cortical volumes. Left planum temporale volume was significantly increased in a subgroup of the participants with WS who demonstrated specific musical strengths, as compared to the remaining WS participants, and was highly correlated with scores on a musical task. These findings suggest that differences in musical ability within WS may be in part associated with variability in the left auditory cortical region, providing further evidence of cognitive and neuroanatomical heterogeneity within this syndrome.

Effect of Musical Experience on Verbal Memory in Williams Syndrome: Evidence from a Novel Word Learning Task.

Williams syndrome (WS) is a neurogenetic developmental disorder characterized by an increased affinity for music, deficits in verbal memory, and atypical brain development. Music has been shown to improve verbal memory in typical individuals as well as those with learning difficulties, but no studies have examined this relationship in WS. The aim of our two studies was to examine whether music can enhance verbal memory in individuals with WS. In Study 1, we presented a memory task of eight spoken or sung sentences that described an animal and identified its group name to 38 individuals with WS. Study 2, involving another group of individuals with WS (n=38), included six spoken or sung sentences that identified an animal group name. In both studies, those who had participated in formal music lessons scored significantly better on the verbal memory task when the sentences were sung than when they were spoken. Those who had not taken formal lessons showed no such benefit. We also found that increased enjoyment of music and heightened emotional reactions to music did not impact performance on the memory task. These compelling findings provide the first evidence that musical experience may enhance verbal memory in individuals with WS and shed more light on the complex relationship between aspects of cognition and altered neurodevelopment in this unique disorder.

Learning without representational change: development of numerical estimation in individuals with Williams syndrome

Experience engenders learning, but not all learning involves representational change. In this paper, we provide a dramatic case study of the distinction between learning and representational change. Specifically, we examined long- and short-term changes in representations of numeric magnitudes by asking individuals with Williams syndrome (WS) and typically developing (TD) children to estimate the position of numbers on a number line. As with TD children, accuracy of WS childrens numerical estimates improved with age (Experiment 1) and feedback (Experiment 2). Both long- and short-term changes in estimates of WS individuals, however, followed an atypical developmental trajectory: as TD children gained in age and experience, increases in accuracy were accompanied by a logarithmic-to-linear shift in estimates of numerical magnitudes, whereas in WS individuals, accuracy increased but logarithmic estimation patterns persisted well into adulthood and after extensive training. These findings suggest that development of numerical estimation in WS is both arrested and atypical.

Adaptive Behavior and Development of Infants and Toddlers with Williams Syndrome

Williams syndrome (WS) is a neurodevelopmental disorder that causes deficits in adaptive behavior, difficulties eating and sleeping, cognitive delays, and delayed development. Although researchers have conducted characterizations of children and adults with WS, less is known about young children with this disorder. This study characterizes the developmental and adaptive behavior features of 16 infants and toddlers with WS aged 3 months – 5 years. Data for this project was obtained from 2007 to 2014, and includes parent report data and standardized developmental testing. Thirty-one percent (31.3%) of parents reported that their infant/toddler with WS had sleeping problems and 58.3% reported feeding difficulties. Levels of adaptive behavior were in the Mildly Delayed range as measured by the Adaptive Behavior Assessment System, Second Edition. Self-care skills such as feeding or dressing oneself were significantly weaker than skills needed to function in the community, such as recognizing his/her home or throwing away trash. The difficulty with self-care skills is hypothesized to be related to the reported difficulties with eating and sleeping. Motor skills were significantly lower than both cognitive and language skills on the Bayley Scales of Infant and Toddler Development, Third Edition. The current study highlights the need for early intervention in these young children across all areas of development, particularly in self-care skills.

Caregiver Survey of Pharmacotherapy to Treat Attention Deficit/Hyperactivity Disorder in Individuals with Williams Syndrome.

Williams syndrome (WS) is a genetic condition characterized by a unique neurocognitive and behavioral profile, including increased incidence of attention deficit/hyperactivity disorder (ADHD). The purpose of the present study was to examine the perceived helpfulness and side effects of medications used to treat ADHD (methylphenidate class, amphetamine class, atomoxetine) in individuals with WS. This was accomplished with a survey of parents/caregivers of individuals with WS through the Williams Syndrome Association. Five-hundred twelve (512) parents/caregivers responded to the survey regarding their childs/adult childs use of ADHD medications. Twenty-seven percent (27%) of the individuals had been prescribed a medication for ADHD, most commonly a methylphenidate class medication. OROS-methylphenidate was reported as the most helpful methylphenidate class formulation, with 74% reporting it at least somewhat helpful. Survey participants reported similar side effects as typically developing controls, but to a greater degree. Irritability was the most commonly endorsed side effect of an ADHD medication (38%). Individuals reported use of stimulant medications in the presence and absence of underlying cardiac conditions, with 56% of ADHD medication users reporting supravalvular aortic stenosis, 36% pulmonary artery stenosis, and 25% systemic hypertension. Individuals taking ADHD medications were more likely to report dental problems (p=0.004). Additional studies are needed to further investigate these findings and examine short-versus long-acting stimulant medications and dosage effects.

Handedness and corpus callosal morphology in Williams syndrome

Williams syndrome is a neurodevelopmental genetic disorder caused by a hemizygous deletion on chromosome 7q11.23, resulting in atypical brain structure and function, including abnormal morphology of the corpus callosum. An influence of handedness on the size of the corpus callosum has been observed in studies of typical individuals, but handedness has not been taken into account in studies of callosal morphology in Williams syndrome. We hypothesized that callosal area is smaller and the size of the splenium and isthmus is reduced in individuals with Williams syndrome compared to healthy controls, and examined age, sex, and handedness effects on corpus callosal area. Structural magnetic resonance imaging scans were obtained on 25 individuals with Williams syndrome (18 right-handed, 7 left-handed) and 25 matched controls. We found that callosal thickness was significantly reduced in the splenium of Williams syndrome individuals compared to controls. We also found novel evidence that the callosal area was smaller in left-handed participants with Williams syndrome than their right-handed counterparts, with opposite findings observed in the control group. This novel finding may be associated with LIM-kinase hemizygosity, a characteristic of Williams syndrome. The findings may have significant clinical implications in future explorations of the Williams syndrome cognitive phenotype.

The proceedings of the 15th professional conference on Williams Syndrome

Williams Syndrome (WS) is a contiguous gene deletion disorder, caused by the deletion of approximately 26–28 genes from chromosome 7 (7q11.23). Individuals with WS have complex medical, developmental, and behavioral features, requiring multidisciplinary and interdisciplinary collaboration. Guidelines detailing the identification, evaluation, and monitoring of individuals with WS need clarification, especially for primary care providers who are first‐line in their management. This report summarizes the proceedings of the 2016 Professional Conference on WS in Columbus, OH. Presentations were directed towards primary care providers and subspecialists, emphasizing evidence‐based practices for treating the prevalent medical and behavioral features of WS. Included in this report are findings from a panel of cardiovascular experts discussing three case studies on treatment of hypertension and the use of sedation or anesthesia for non‐cardiac procedures. Abstracts from individual expert presenters are included, covering various medical and behavioral topics, and providing updates in management of WS individuals. The following topics were discussed: differences in phenotypes of 7q11.23 deletion versus duplication, growth parameters, endocrine concerns, sleep difficulties, behaviors to monitor, and pharmacological options, the neurodevelopmental profile of WS individuals, and the importance of monitoring medical and behavioral concerns as WS individuals transition to adulthood.

Music lessons are associated with increased verbal memory in individuals with Williams syndrome

Williams syndrome (WS) is a genetic disorder characterized by intellectual delay and an affinity for music. It has been previously shown that familiar music can enhance verbal memory in individuals with WS who have had music training. There is also evidence that unfamiliar, or novel, music may also improve cognitive recall. This study was designed to examine if a novel melody could also enhance verbal memory in individuals with WS, and to more fully characterize music training in this population. We presented spoken or sung sentences that described an animal and its group name to 44 individuals with WS, and then tested their immediate and delayed memory using both recall and multiple choice formats. Those with formal music training (average duration of training 4½ years) scored significantly higher on both the spoken and sung recall items, as well as on the spoken multiple choice items, than those with no music training. Music therapy, music enjoyment, age, and Verbal IQ did not impact performance on the memory tasks. These findings provide further evidence that formal music lessons may impact the neurological pathways associated with verbal memory in individuals with WS, consistent with findings in typically developing individuals.