Diabetes Mellitus in Prader-Willi Syndrome: Natural History during the Transition from Childhood to Adulthood in a Cohort of 39 Patients

Type 2 diabetes mellitus in people with intellectual disabilities: Examining incidence, risk factors, quality of care and related complications. A population-based matched cohort study

AIMS

People with intellectual disabilities are at higher risk of type 2 diabetes mellitus (T2DM) but there are currently gaps in our understanding related to risk of new onset, care of T2DM and complications.

METHODS

We examined electronic health-record data from Jan 2010 to May 2022 in 189,172 people with intellectual disabilities and 306,697 age, sex and family practice matched controls. We estimated incidence rates per 1,000-person-years, incidence rate ratios (IRRs), risk factors for T2DM (odds ratio, OR), indicators of quality of care and complications (hazard ratio, HR).

RESULTS

Incidence of T2DM in people with intellectual disabilities was 3.74 compared to 2.21 per 1,000 person-years in controls. After allowing for the younger age of T2DM onset in intellectual disabilities, the adjusted IRR was 6.91 (95 % CI 5.81-8.22). Impaired mobility was associated with T2DM incidence in people with intellectual disabilities (OR = 7.72, 5.87-10.15). People with intellectual disabilities received blood tests for HbA1c and cholesterol, and eye and foot examinations less often; and had a 12 % higher risk of developing macrovascular complications.

CONCLUSIONS

People with intellectual disabilities are at increased risk of T2DM at younger ages, have specific risk factors, experience inequities in care and are at risk for macrovascular complications.

A Male Japanese Patient with Temple Syndrome Complicated by Type 2 Diabetes Mellitus

We herein present the case of a 21-year-old male Japanese diabetic patient with Temple syndrome, caused by maternal uniparental disomy of chromosome 14. The patient was overweight and had type 2 diabetes, dyslipidemia, metabolic dysfunction-associated steatotic liver disease, and microalbuminuria. He had an increased fat mass in the truncal region and a decreased lean mass throughout the body. This may lead to insulin resistance due to the absence of delta-like homolog 1 (DLK1) and retrotransposon gag-like 1 (RTL1). The patient had experienced social withdrawal at home (hikikomori in Japanese), had poorly controlled type 2 diabetes, and was overweight despite receiving diet therapy and oral hypoglycemic agents.

Genomic Regions Associated with Growth and Reproduction Traits in Pink-Eyed White Mink

In mink breeding, balanced selection for growth and reproductive features is essential because these traits are contradictory. The variables of total number born (TNB), number born alive (NBA), and body weight (BW) are highly valuable in terms of their importance in mink production. A comprehensive understanding of the molecular mechanisms that drive these features could offer vital insights into their genetic compositions. In the present study, the single-nucleotide polymorphism (SNP) genotypes of 219 minks were obtained via double digest restriction-site associated DNA sequencing (ddRAD-seq). Following several rounds of screening, about 2,415,121 high-quality SNPs were selected for a genome-wide association study (GWAS). The GWAS was used to determine BW and reproductive traits in pink-eyed white mink. It was suggested that SLC26A36, STXBP5L, and RPS 29 serve as potential genes for the total number of kits born (TNB), while FSCB, PDPN, NKX 2-1, NFKB 1, NFKBIA, and GABBR1 are key genes for the number born alive (NBA). Moreover, RTTN, PRPF31, MACROD1, and KYAT1 are possible BW genes based on association results and available functional data from gene and mammalian phenotype databases. These results offer essential information about the variety of mink and theoretical principles for applying mink breeds.

Prader-Willi syndrome: guidance for children and transition into adulthood

Prader-Willi syndrome (PWS) is a rare orphan disease and complex genetic neurodevelopmental disorder, with a birth incidence of approximately 1 in 10,000-30,000. Management of people with PWS requires a multi-disciplinary approach, ideally through a multi-disciplinary team (MDT) clinic with community support. Hypotonia, poor feeding and faltering growth are characteristic features in the neonatal period, followed by hyperphagia and risk of rapid weight gain later in childhood. Children and adolescents (CA) with PWS usually display developmental delay and mild learning disability and can develop endocrinopathies, scoliosis, respiratory difficulties (both central and obstructive sleep apnoea), challenging behaviours, skin picking, and mental health issues, especially into adulthood. This consensus statement is intended to be a reference document for clinicians managing children and adolescents (up to 18 years of age) with PWS. It considers the bio-psycho-social domains of diagnosis, clinical assessment, and management in the paediatric setting as well as during and after transition to adult services. The guidance has been developed from information gathered from peer-reviewed scientific reports and from the expertise of a range of experienced clinicians in the United Kingdom and Ireland involved in the care of patients with PWS.

Imprinting disorders

Imprinting disorders (ImpDis) are congenital conditions that are characterized by disturbances of genomic imprinting. The most common individual ImpDis are Prader-Willi syndrome, Angelman syndrome and Beckwith-Wiedemann syndrome. Individual ImpDis have similar clinical features, such as growth disturbances and developmental delay, but the disorders are heterogeneous and the key clinical manifestations are often non-specific, rendering diagnosis difficult. Four types of genomic and imprinting defect (ImpDef) affecting differentially methylated regions (DMRs) can cause ImpDis. These defects affect the monoallelic and parent-of-origin-specific expression of imprinted genes. The regulation within DMRs as well as their functional consequences are mainly unknown, but functional cross-talk between imprinted genes and functional pathways has been identified, giving insight into the pathophysiology of ImpDefs. Treatment of ImpDis is symptomatic. Targeted therapies are lacking owing to the rarity of these disorders; however, personalized treatments are in development. Understanding the underlying mechanisms of ImpDis, and improving diagnosis and treatment of these disorders, requires a multidisciplinary approach with input from patient representatives.

CD16+ monocytes are involved in the hyper-inflammatory state of Prader-Willi Syndrome by single-cell transcriptomic analysis

Background

Patients with Prader-Willi syndrome (PWS) have a reduced life expectancy due to inflammation-related disease including cardiovascular disease and diabetes. Abnormal activation of peripheral immune system is postulated as a contributor. However, detailed features of the peripheral immune cells in PWS have not been fully elucidated.

Methods

Serum inflammatory cytokines were measured in healthy controls (n=13) and PWS patients (n=10) using a 65- multiplex cytokine assays. Changes of the peripheral immune cells in PWS was assessed by single-cell RNA sequencing (scRNA-seq) and high-dimensional mass cytometry (CyTOF) using peripheral blood mononuclear cells (PBMCs) from PWS patients (n=6) and healthy controls (n=12).

Results

PWS patients exhibited hyper-inflammatory signatures in PBMCs and monocytes were the most pronounced. Most inflammatory serum cytokines were increased in PWS, including IL-1β, IL-2R, IL-12p70, and TNF-α. The characteristics of monocytes evaluated by scRNA-seq and CyTOF showed that CD16⁺ monocytes were significantly increased in PWS patients. Functional pathway analysis revealed that CD16⁺ monocytes upregulated pathways in PWS were closely associated with TNF/IL-1β- driven inflammation signaling. The CellChat analysis identified CD16⁺ monocytes transmitted chemokine and cytokine signaling to drive inflammatory process in other cell types. Finally, we explored the PWS deletion region 15q11-q13 might be responsible for elevated levels of inflammation in the peripheral immune system.

Conclusion

The study highlights that CD16⁺ monocytes contributor to the hyper-inflammatory state of PWS which provides potential targets for immunotherapy in the future and expands our knowledge of peripheral immune cells in PWS at the single cell level for the first time.

Reference Genes across Nine Brain Areas of Wild Type and Prader-Willi Syndrome Mice: Assessing Differences in Igfbp7, Pcsk1, Nhlh2 and Nlgn3 Expression

Prader−Willi syndrome (PWS) is a complex neurodevelopmental disorder caused by the deletion or inactivation of paternally expressed imprinted genes at the chromosomal region 15q11−q13. The PWS-critical region (PWScr) harbors tandemly repeated non-protein coding IPW-A exons hosting the intronic SNORD116 snoRNA gene array that is predominantly expressed in brain. Paternal deletion of PWScr is associated with key PWS symptoms in humans and growth retardation in mice (PWScr model). Dysregulation of the hypothalamic−pituitary axis (HPA) is thought to be causally involved in the PWS phenotype. Here we performed a comprehensive reverse transcription quantitative PCR (RT-qPCR) analysis across nine different brain regions of wild-type (WT) and PWScr mice to identify stably expressed reference genes. Four methods (Delta Ct, BestKeeper, Normfinder and Genorm) were applied to rank 11 selected reference gene candidates according to their expression stability. The resulting panel consists of the top three most stably expressed genes suitable for gene-expression profiling and comparative transcriptome analysis of WT and/or PWScr mouse brain regions. Using these reference genes, we revealed significant differences in the expression patterns of Igfbp7, Nlgn3 and three HPA associated genes: Pcsk1, Pcsk2 and Nhlh2 across investigated brain regions of wild-type and PWScr mice. Our results raise a reasonable doubt on the involvement of the Snord116 in posttranscriptional regulation of Nlgn3 and Nhlh2 genes. We provide a valuable tool for expression analysis of specific genes across different areas of the mouse brain and for comparative investigation of PWScr mouse models to discover and verify different regulatory pathways affecting this complex disorder.