Causes of death in Prader-Willi syndrome: lessons from 11 years' experience of a national reference center.

BACKGROUND: In the last 20 years, substantial improvements have been made in the diagnosis, treatment and management of patients with Prader-Willi syndrome (PWS). Few data on causes of death are available since those improvements were made. Our study assessed the causes of death among French patients with PWS over the first 11 years of experience of the nationwide French Reference Center for PWS (FRC-PWS). METHODS: Our study relied on two sources of mortality information at national level between 2004 and 2014: The French Epidemiological Centre for the Medical Causes of Death (CépiDc) Registry and the FRC-PWS database. Causes of death were classified into seven categories: respiratory, cardiovascular, gastrointestinal, severe infection, sudden death, other causes, and unknown. Descriptive statistics were calculated separately for children (< 18 years-old) and adults (≥18 years-old). RESULTS: One hundred and four deaths were identified in France from 2004 to 2014. The median age at death was 30 years, ranging from less than 1 month to 58 years. Seventeen deaths occurred in patients under 18 years, with 70% of them in children under 2 years. Respiratory causes accounted for more than 50% of the deaths in patients with PWS in both children and adults. Both cause and age of death did not significantly differ according to gender or genetic subtype. CONCLUSIONS: Patients with PWS die prematurely due to a respiratory cause in most cases at all ages. In those adult patients with data on obesity, 98% were reported to be obese.

Venous Thromboembolism in Prader-Willi Syndrome: A Questionnaire Survey.

Prader-Willi Syndrome Association (USA) monitors the ongoing health and welfare of individuals with Prader-Willi syndrome (PWS) through active communication with members by membership surveys and data registries. Thromboembolism and blood clots have emerged in clinical studies as significant risk factors for injury and death in PWS. A 66-item questionnaire was developed by a panel of PWS medical and scientific experts, with input from Prader-Willi Syndrome Association (USA) leadership, so as to probe their membership on the frequency, risk, and protective factors for venous thromboembolism, pulmonary embolism, and related findings. The characteristics of those with and without a reported history of blood clots and related health factors were tabulated and analyzed. Responses were obtained for 1067 individuals with PWS (554 females and 513 males), and 38 (23 females and 15 males) had a history of blood clots. The individuals with clots did not differ by gender, but were significantly older 32.8 ± 15 years vs 20.4 ± 13 years, and were more likely to have a reported history of obesity (76%), edema (59%), hypertension (24%), vasculitis (33%), and family history of blood clots (33%) than those without clots. Growth hormone treatment was more common in individuals without clots. The risk factors for thromboembolism in PWS overlap those commonly observed for the general population.

Contributing factors of mortality in Prader-Willi syndrome.

Prader-Willi syndrome (PWS) is a multi-system disorder resulting from a lack of paternal gene expression in the 15q11.2-q13 region. Using databases compiled through response questionnaires completed by families known to the Prader-Willi Syndrome Association (USA), this study tested the hypothesis that PWS genetic subtype, BMI, age of diagnosis, clinical symptoms, and growth hormone treatment differ among deceased and living individuals with PWS. Categorical and continuous variables were compared using chi-square and two-group t tests, respectively. Deceased individuals had higher rates of clinical features, including increased weight concerns, heart problems, sleep apnea, other respiratory complications, diabetes, osteoporosis, high pain tolerance, and severe skin picking, when compared to living individuals. Meanwhile, living individuals had higher rates of growth hormone use and early puberty. Obesity and subsequent consequences are the primary contributors to increased mortality in PWS. Additional emphasis on areas to decrease mortality is needed.

Ghrelin Receptor Agonist Rescues Excess Neonatal Mortality in a Prader-Willi Syndrome Mouse Model.

In the current study, we sought to determine the significance of the ghrelin system in Prader-Willi Syndrome (PWS). PWS is characterized by hypotonia and difficulty feeding in neonates and hyperphagia and obesity beginning later in childhood. Other features include low GH, neonatal hypoglycemia, hypogonadism, and accelerated mortality. Although the hyperphagia and obesity in PWS have been attributed to elevated levels of the orexigenic hormone ghrelin, this link has never been firmly established, nor have ghrelin's potentially protective actions to increase GH secretion, blood glucose, and survival been investigated in a PWS context. In the current study, we show that placing Snord116del mice modeling PWS on ghrelin-deficient or ghrelin receptor [GH secretagogue receptor (GHSR)]-deficient backgrounds does not impact their characteristically reduced body weight, lower plasma IGF-1, delayed sexual maturation, or increased mortality in the period prior to weaning. However, blood glucose was further reduced in male Snord116del pups on a ghrelin-deficient background, and percentage body weight gain and percentage fat mass were further reduced in male Snord116del pups on a GHSR-deficient background. Strikingly, 2 weeks of daily administration of the GHSR agonist HM01 to Snord116del neonates markedly improved survival, resulting in a nearly complete rescue of the excess mortality owing to loss of the paternal Snord116 gene. These data support further exploration of the therapeutic potential of GHSR agonist administration in limiting PWS mortality, especially during the period characterized by failure to thrive.

Survival trends from the Prader-Willi Syndrome Association (USA) 40-year mortality survey.

PurposePrader-Willi syndrome (PWS) is a complex genetic disorder characterized by hyperphagia and morbid obesity with increased cardiopulmonary and hyperphagia-related mortality. Survival trends in PWS were evaluated to assess the impact of modern interventions on mortality risk.MethodsThe Prader-Willi Syndrome Association (USA) 40-year mortality syndrome-specific database of 486 death reports was utilized to examine survival trends in PWS and cohort effects for recent deaths (years 2000-2015, N=331) relative to deaths prior to 2000 (N=94). Cox proportional hazards regression modeling was applied to generate log rank statistics and Kaplan-Meier curves examining sex, cause of death, and cohort.ResultsRisk for all-cause mortality in PWS was 1.5 (95% confidence interval (CI)=1.2-1.9) times higher for the Early than the Recent era cohort reflected in female cardiac failure (hazard ratio (HR)=1.8; 95% CI=1.3-2.6), pulmonary embolism (HR=6.1; 95% CI=1.7-22), and gastrointestinal-related (HR=3.2; 95% CI=1.1-7.4) causes. Accidental deaths in males increased in the Recent era cohort (HR=5.7; 95% CI=1.2-27.1), possibly due to enhanced weight management and mobility. Risk of death from respiratory failure was unchanged.ConclusionWe report measurable increases in survival effecting cardiovascular and gastrointestinal-related causes in PWS most likely attributable to earlier diagnosis and proactive interventions to prevent morbid obesity. More research is needed to address underlying vulnerability to respiratory failure, an unchanged mortality risk in PWS.

Causes of death in Prader-Willi syndrome: Prader-Willi Syndrome Association (USA) 40-year mortality survey.

BACKGROUND: Prader-Willi syndrome (PWS) is a rare, complex, neurodevelopmental genetic disorder that is associated with hyperphagia and morbid obesity in humans and leads to a shortened life expectancy. This report summarizes the primary causes of death and evaluates mortality trends in a large cohort of individuals with PWS. METHODS: The US Prader-Willi Syndrome Association (PWSA (USA)) syndrome-specific database of death reports was collected through a cursory bereavement program for PWSA (USA) families using a brief survey created in 1999. Causes of death were descriptively characterized and statistically examined using Cox proportional hazards. RESULTS: A total of 486 deaths were reported (263 males, 217 females, 6 unknown) between 1973 and 2015, with mean age of 29.5 ± 16 years (2 months-67 years); 70% occurred in adulthood. Respiratory failure was the most common cause, accounting for 31% of all deaths. Males were at increased risk for presumed hyperphagia-related accidents/injuries and cardiopulmonary factors compared to females. PWS maternal disomy 15 genetic subtype showed an increased risk of death from cardiopulmonary factors compared to the deletion subtype. CONCLUSIONS: These findings highlight the heightened vulnerability to obesity and hyperphagia-related mortality in PWS. Future research is needed to address critical vulnerabilities such as gender and genetic subtype in the cause of death in PWS.Genet Med advance online publication 17 November 2016.

Ageing in people with Prader-Willi syndrome: mortality in the UK population cohort and morbidity in an older sample of adults.

BACKGROUND: The past two decades have seen a great improvement in the care of people with Prader-Willi syndrome (PWS), particularly with regard to control of diet and behaviour management. Has this affected mortality rates or thrown up new issues regarding premature ageing or dementia? We investigated two aspects of ageing in people with PWS: (1) an estimate of mortality over 9 years in a cohort of people with PWS, originally recruited in 1998-2000; and (2) premature ageing or dementia in people aged ⩾40 years. METHOD: (1) A follow-up of the population-based 1998-2000 cohort to investigate the subsequent mortality rate; and (2) the recruitment and structured assessment of all members of the Prader-Willi Syndrome Association UK (PWSA-UK) aged ⩾40 years who agreed to participate. RESULTS: Follow-up of the population-based 1998-2000 cohort gave a mortality rate of at least 7/62 over 9 years (1.25% per annum; 20 untraced), age at death was between 13 and 59 years. Twenty-six members of the PWSA-UK aged ⩾40 years were recruited, 18 of whom had a genetic diagnosis (gd) of PWS. Twenty-two (14 gd) showed no evidence of dementia. Four, with possible symptoms, are described in more detail; all are female, of maternal uniparental disomy (mUPD) genetic subtype, or have a disomic region, and all have a long history of psychotic illness. CONCLUSIONS: The mortality rate in people with PWS seems to be declining. The subgroup of people with PWS due to UPD or disomic region with female gender and a history of psychosis may be at risk of early onset dementia.

Prader-Willi syndrome in Victoria: mortality and causes of death.

AIM: The aim of this study was to describe the rates, predictors and causes of mortality in a population sample of individuals with Prader-Willi syndrome (PWS). METHODS: One hundred sixty-three individuals with PWS (90 males and 73 females, ages: 3 weeks to 60 years) were identified from the Victorian PWS Register. Information on demographics, age at diagnosis, genetic mechanism, age at which obesity developed and last known body mass index measurement were extracted. Notification and causes of death were obtained through linkage with Australian national and state of Victoria death indexes. Survival analysis was used to estimate the probability of survival and the effect of obesity on survival. Mortality rate ratios were calculated to investigate the effect of the factors listed above on mortality. RESULTS: Fifteen deaths were recorded (nine males and six females), corresponding to an 87% probability of survival to 35 years. The probability of survival was significantly lower for individuals with known obesity (P= 0.03), but there was no strong evidence for an effect on survival for the other factors studied. Cardiac or respiratory conditions were common causes of death after the age of 15 years. CONCLUSIONS: The effect of known obesity on the probability of survival and the causes of death reported in this and other studies suggest an important association between obesity and early death in adults with PWS. This finding highlights the critical nature of preventative and intervention strategies aimed at minimising the effects of hyperphagia in individuals with PWS.

Review of 64 cases of death in children with Prader-Willi syndrome (PWS).

Several deaths have been reported in children with Prader-Willi syndrome (PWS) following treatment with growth hormone (GH). We collected all of the reports of deaths in PWS children, both in treatment and non-treatment groups, analyzed the causes of the death and compared the two groups. We conducted an exhaustive search for reports using bibliographic databases, toxicology pharmacovigilance databases, and personal communications. Sixty-four PWS children (42M/22F) aged from a few days to 19 years were identified, 28 received GH treatment. Our results show that respiratory disorders were the most common cause of death (respiratory insufficiency or infections) which were reported in 61% of the children (68% in GH-treated and 55.5% in -untreated patients). We found no significant differences in gender, prevalence of obesity or prevalence of sleep apnea, between the patients treated with GH and the untreated patients. Nevertheless, most of the deaths in GH-treated children (75%) occurred during the first 9 months after the initiation of GH treatment. Our analysis shows the high frequency of respiratory infections in both GH-treated and -untreated PWS children. The first 9 months of GH treatment seems to be a high-risk period emphasizing the need for comprehensive care before and during GH treatment.

Deaths due to choking in Prader-Willi syndrome.

Prader-Willi syndrome (PWS) is the most common known syndromic cause of life-threatening obesity, yet few studies have examined the causes of death in PWS. The objective of this study was to examine the contribution of choking leading to mortality in PWS. In 1999, a brief survey was made available from the Prader-Willi Syndrome Association (USA) bereavement program, which documented demographic data and causes of death. Families were subsequently offered the opportunity to fill out a detailed questionnaire and additional forms to release medical records. Demographic information was available on 178 deceased individuals with PWS, and cause of death available on 152 individuals. Fifty-four families completed questionnaires. Of the deceased individuals with completed questionnaires, 34% reported a history of choking. Choking was listed by familial report as the cause of death in 12 (7.9%) of 152 subjects with an average age of 24 years (range 3-52 years; median 22.5 years) at death from choking. Only two of these individuals were less than 8 years of age. The data suggest that risks associated with choking are different in the PWS population compared with others. Potential causes of increased choking in PWS include poor oral/motor coordination, poor gag reflex, hypotonia, hyperphagia, decreased mastication, and voracious feeding habits. We recommend implementation of preventive measures and education for families and group home care providers for all individuals with PWS including the Heimlich maneuver, supervised meals, better food preparation, and diet modification to avoid high-risk choking items.

Growth hormone treatment and adverse events in Prader-Willi syndrome: data from KIGS (the Pfizer International Growth Database).

OBJECTIVE: To evaluate the response to recombinant GH treatment and adverse events in children with Prader-Willi syndrome (PWS) from KIGS, the Pfizer International Growth Database. PATIENTS: A total of 328 children (274 prepubertal, median age 6.0 years; 54 pubertal, median age 12.7 years) were treated for 1 year and 161 children were treated for 2 years with GH. RESULTS: Height standard deviation score (SDS) increased significantly during treatment; the response was greater in prepubertal (-0.7 vs.-1.8 pretreatment) compared with pubertal children (-1.5 vs.-1.8). Predictors of first-year height velocity in multiple regression analysis were GH dose, body weight (positively correlated), height SDS minus mid-parental height SDS and chronological age (negatively correlated), together accounting for 39% of the variation in response to GH. Body mass index (BMI) SDS did not change significantly during 2 years of treatment. Of all the 675 GH-treated PWS patients in KIGS, there were five cases of sudden death (age range 3-15 years). Three were obese (weight for height > 200%) and causes of death included bronchopneumonia, respiratory insufficiency and sleep apnoea. Scoliosis was the most commonly reported adverse event (n = 24), four children developed hyperglycaemia and six had presumptive diabetes (type 2 in five, and one case of type 1). CONCLUSIONS: Short-term growth improved in response to conventional doses of GH in children with PWS. Prior to commencement of GH, examination of the upper airways and sleep studies should be performed in PWS patients. GH should be used with caution in those with extreme obesity or disordered breathing and all patients should be closely monitored for adverse events.

Mortality in Prader-Willi syndrome.

Persons with Prader-Willi syndrome have been known to have a high mortality rate. However, intellectual disability, which usually accompanies Prader-Willi syndrome, is also associated with a higher mortality rate than in the general population. In this study, the death rates in a longitudinal cohort of people with Prader-Willi syndrome are compared with those for an epidemiologically derived control sample of people with intellectual disability from other causes. We found that those with Prader-Willi syndrome had a higher mortality rate than did controls. After the protective effect of mild intellectual disability or average intellectual function was accounted for, the hazard ratio for Prader-Willi syndrome versus controls was 6.07. Obesity and its complications were factors contributing to the mortality identified in this study.

Death during GH therapy in children with Prader-Willi syndrome: description of two new cases.

A few cases of death worldwide during GH treatment in pediatric patients with Prader-Willi syndrome (PWS) have been recently described. The evaluation of further cases is needed to better identify possible causal mechanism(s), as well as to suggest some additional guidelines for prevention. We report the death of 2 additional children with genetically confirmed PWS in the first months of GH therapy. Case 1: This 3.9-yr-old girl was born at 39 weeks gestation. Low GH response to two stimulation tests was observed. GH administration was started at the age of 3.5 yr (0.33 mg/kg per week), when the patient was at 130% of her ideal body weight (ibw). Hypertrophy of adenoids was previously demonstrated. Snoring and sleep apnea were present before GH treatment, and did not increase during therapy. Four months later she died at home suddenly in the morning. Case 2: This patient was a 6.3-yr-old boy. He was born at term after an uneventful pregnancy. At the age of 6 yr, his weight was at 144% of his ibw. He showed reduced GH secretion during provocation tests, and GH therapy was started (0.20 mg/kg per week). The previously reported nocturnal respiratory impairment had worsened after beginning GH administration. Tonsils and adenoids hypertrophy were noted. At the age of 6.3 yr he died at home in the morning following an acute crisis of apnea. These additional cases seem to confirm that some children with PWS may be at risk of sudden death at the beginning of GH therapy.

Cause of sudden, unexpected death of Prader-Willi syndrome patients with or without growth hormone treatment.

Patients with Prader-Willi syndrome (PWS) are recognized to have a tendency of sudden, unexpected death (SED), but its exact cause is unknown because of paucity of such case reports. Since growth hormone (GH) treatment was applied to PWS patients worldwide, several cases of death have been reported. However, whether the therapy is directly related to their SED remains unknown, too. We collected 13 deceased PWS patients (Group A, aged 9 months to 34 years) who had never received GH therapy, and seven deceased patients (Group B, all boys aged 0.7-15 years) having received the therapy from the registration in PWS-patient-support associations and from the literature, respectively. We then compared the cause of SED between the two groups. Irrespective of GH therapy, SED of infants under age 1 year was associated with milk aspiration or hypothalamic dysregulation of respiration, while SED of patients in early childhood or adolescence occurred at sleeping in association with preceding viral infections. In contrast, SED of four adult (>20 years of age) patients who never received GH therapy was associated with complications, such as leg cellulites and pulmonary embolism, secondary to massive obesity and diabetes mellitus (DM). Two Group-B patients (aged 14 and 20 years) without any obesity-related or diabetes-related complications died of drowning in a bath tub, and their drowning death could be related to poor respiratory control. These findings indicated that the cause of SED is not essentially different between PWS patients with and without GH treatment. Deceased PWS patients may have had underlying respiratory dysregulation and hypothalamic dysfunction, and GH therapy might have led to certain obstructive respiratory disturbances that exacerbated the respiratory conditions. This will call clinicians' attention when using GH in PWS patients, for example, careful determination of the dose of GH and careful monitoring of patient's respiratory conditions, especially in male obese patients with respiratory problems.

Deaths in children with Prader-Willi syndrome. A contribution to the debate about the safety of growth hormone treatment in children with PWS.

Irrespective of GH treatment, children with Prader-Willi syndrome (PWS) suffer more frequently and more seriously from respiratory problems than healthy children. The pathogenesis of such respiratory problems in PWS seems to be multifactorial in origin, but mainly related to insufficiency of respiratory muscles and pharyngeal narrowness. Deaths of children with PWS are reported among GH treated as well as untreated children. Our data show that also disturbed body composition plays an important role in fatal outcomes, possibly enhancing the ventilation disorder. For several years, in our recommendations we have pointed out the secondary risks of increasing obesity. In addition, it is recommended for all children with PWS, in particular before institution of GH therapy, to have polysomnography and an otorhinolaryngologic examination performed, and tonsillectomy in the case of enlarged tonsils. Furthermore, upper airway infections should be treated aggressively.

Prader-Willi syndrome: causes of death in an international series of 27 cases.

Prader-Willi syndrome (PWS) is a complex condition with many medical and psychological features. In individuals with this syndrome, causes of death were studied. Data of 27 case reports were collected. Ages at death ranged from neonatal to 68 years. None of the individuals were treated with growth hormone (GH). Most cases were not completely documented and autopsy was performed in a minority of cases only. In five cases, death was considered not to be causally related to PWS. Hypotonia with hypoventilation was noted in the babies, and acute respiratory illness with unexpected sudden death was experienced in young children with PWS. Two young children died after a short period of fever and gastroenteritis. Obesity and its complications leading to death were pronounced in the adult group. One (possibly two) adult(s) died from gastric dilatation and shock. Based on these data, some cautious conclusions can be drawn. In babies with PWS hypoventilation is a risk factor; upper airway infection may be more serious than anticipated and any other clinical features pointing to an infection should be taken very seriously. Therefore, young infants with PWS hospitalized with an upper airway infection and/or hypoventilation or gastroenteritis symptoms, should be closely monitored. Early diagnosis and prevention of overweight is a major factor in preventing early causes of death in individuals with PWS. In the adult group, weight reduction is important but difficult to manage. Sleep apnea should be recognized and treated. Pain in the upper stomach and/or vomiting should be taken as a possible sign of acute intestinal dilatation; intravenous support may be life saving.