Genetic screening reveals hotspot variants and prevalence rates of Hermansky-Pudlak syndrome in the Chinese population.

BACKGROUND: Hermansky-Pudlak Syndrome (HPS) is a rare autosomal recessive genetic disorder associated with varied clinical manifestations, including oculocutaneous albinism, bleeding tendency, and systemic complications. Early and accurate diagnosis is crucial for medical interventions and genetic counseling. We aimed to characterize the prevalence and spectrum of pathogenic variants of HPS in the Chinese population through genetic screening of newborns. METHODS: Genetic screening for HPS mutations was conducted in 29,622 Chinese newborns from 13 provinces using next-generation sequencing. Pathogenic variants were identified and classified according to ACMG guidelines. Prevalence rates were estimated, and potential hotspot variants were identified. RESULTS: Among screened newborns, 215 carriers with 103 distinct pathogenic variants were identified, including two carriers with additional missense variants. Potential hotspot variants in seven genes were identified, collectively representing over 20 % of carriers in each respective gene. Particularly, the HPS3 c.1838C>G variant was exclusively reported in the Chinese population, suggesting a potential founder effect. The estimated prevalence rate of HPS in China was 2.84/1,000,000. CONCLUSION: Our study provides valuable insights into the genetic landscape of HPS in the Chinese population, aiding in genetic counseling, early diagnosis, and management strategies. These findings contribute to enhancing the understanding and management of HPS in China.

Hermansky-Pudlak Syndrome: Spectrum in Oman.

Hermansky-Pudlak syndrome (HPS) is a rare autosomal recessive disorder, characterized by oculocutaneous albinism, a hemorrhagic diathesis secondary to storage pool-deficient platelets, and in some patients' pulmonary fibrosis, granulomatous colitis, and immunodeficiency. To date, 11 different types of Hermansky-Pudlak syndrome were identified. HPS type 2 is distinctively characterized by severe neutropenia and recurrent sinopulmonary infections. HPS is more common in Puerto Rico, and this is the first report deciphering the genotypic spectrum of HPS in Oman. Between 2001 and 2021, 8 Omani cases with HPS (3 HPS type 2, 1 HPS type 3, and 4 HPS type 6) had been suspected clinically and confirmed through genetic mutation analysis. Patients had mild hemorrhagic phenotype, and variable platelet aggregation defects with different platelet agonists. All patients had characteristic eye manifestations. In addition, patients with HPS type 2 had severe neutropenia. Novel mutations in AP3B1(c.205-1G>C, c.12_13delTA (p.Asn4Lysfs*6) and HPS6 (c.19_20delCT (p. Leu7Alafs*168) were not reported in population variant databases. Diagnosis of HPS had markedly improved in Oman; however, increased clinician awareness is needed. A high index of suspicion and early referral for diagnosis and initiation of proper treatment might help improve outcomes.

Dermatologic manifestations in patients with the Hermansky-Pudlak syndrome types 1 and 3.

BACKGROUND: The Hermansky-Pudlak syndrome (HPS) is a genetically heterogeneous group of diseases characterized by oculocutaneous albinism, bleeding diathesis, and systemic complications. It is the most common genetic disorder in Puerto Rico. These patients are at a significant risk of developing a variety of skin complications and little is known about the prevalence of dermatologic diagnoses in this population. OBJECTIVES: To report dermatologic manifestations in patients with Hermansky-Pudlak syndrome (HPS). Secondary aims include skin concerns, sun protection habits, barriers to dermatologic care, and skin cancer knowledge. METHODS: Cross-sectional study with twenty-nine Puerto Rican patients who carried a clinical diagnosis of HPS type 1 or type 3 through a telephonic questionnaire. RESULTS: Twenty-nine patients participated with a mean (SD) age of 37.3 (16.8) years and the majority were female (69%). The most common diagnoses were skin cancer (34.5%), acne (34.5%), bacterial skin infections (34.5%), warts (24%), urticaria (17.2%), and psoriasis (17.2%). The most common skin concerns were dry skin (62.1%), hair loss (58.9%), redness (34.5%), moles (31%), and rash (31%). The most common sun protection behavior was wearing a shirt that covers the shoulders (93.1%, often or always) and the least common was wearing a hat (24.1%, often or always). Higher income was significantly associated with being more likely to use sunscreen often or always (OR = 3.38, 95% CI 1.02-11.18, p = 0.04). Those in northern urban areas were significantly less likely to report barriers to dermatologic care (OR = 0.13, 95% CI 0.02-0.76, p = 0.02). CONCLUSIONS: This study provides an important overview of the most common self-reported skin manifestations in patients with HPS. Unfortunately, a high prevalence of cutaneous malignancy was reported. The results stress the need for adequate care and potential interventions to promote sun protection behaviors and skin cancer prevention.

Hermansky-Pudlak Syndrome.

Hermansky-Pudlak syndrome (HPS) is a multisystemic autosomal recessive disorder characterized by oculocutaneous albinism, bleeding diathesis, and lethal pulmonary fibrosis (PF) in some HPS subtypes. During middle adulthood, ground-glass opacities, reticulation, and traction bronchiectasis develop with progression of PF. HPS is an orphan disease occurring in 1 in 500,000 to 1,000,000 individuals worldwide, though the prevalence is 1 in 1,800 in individuals with Puerto Rican heritage. Recessive mutations or disruptions in HPS genes alter the function of HPS proteins which are components of biogenesis of lysosome-related organelle complexes and are critical for intracellular protein trafficking. Diagnosis and management of HPS-related comorbidities represent a challenge to physicians, and a multidisciplinary clinical approach is necessary for early detection, health management, and surveillance of PF in patients with HPS types 1, 2, and 4. Treatment options for individuals with HPS-PF include pirfenidone and lung transplantation. In this article, we describe the epidemiology, genetics, clinical manifestations, and management of HPS.

Modeling of Fibrotic Lung Disease Using 3D Organoids Derived from Human Pluripotent Stem Cells.

The pathogenesis of idiopathic pulmonary fibrosis (IPF), an intractable interstitial lung disease, is unclear. Recessive mutations in some genes implicated in Hermansky-Pudlak syndrome (HPS) cause HPS-associated interstitial pneumonia (HPSIP), a clinical entity that is similar to IPF. We previously reported that HPS1-/- embryonic stem cell-derived 3D lung organoids showed fibrotic changes. Here, we show that the introduction of all HPS mutations associated with HPSIP promotes fibrotic changes in lung organoids, while the deletion of HPS8, which is not associated with HPSIP, does not. Genome-wide expression analysis revealed the upregulation of interleukin-11 (IL-11) in epithelial cells from HPS mutant fibrotic organoids. IL-11 was detected predominantly in type 2 alveolar epithelial cells in end-stage IPF, but was expressed more broadly in HPSIP. Finally, IL-11 induced fibrosis in WT organoids, while its deletion prevented fibrosis in HPS4-/- organoids, suggesting IL-11 as a therapeutic target. hPSC-derived 3D lung organoids are, therefore, a valuable resource to model fibrotic lung disease.

The lived experience of having a rare medical disorder: Hermansky-Pudlak syndrome.

Hermansky-Pudlak Syndrome is a rare form of albinism, affecting approximately one in 500,000 to one in 1,000,000 non-Hispanic individuals. The syndrome is more commonly found in Hispanics, where one in 18,00 individuals in Northwestern Puerto Rico are impacted. Because of the rarity of this chronic condition, patients often face challenges in their ability to cope with the diagnosis. A phenomenological study was conducted to explore the experience of individuals with this rare genetic disease. A purposive sample of adults between the ages of 20 and 49 diagnosed with Hermansky-Pudlak Syndrome was interviewed (N = 23). The majority (83%) were female. Data analysis resulted in the emergence of themes related to long road to diagnosis, learning to move forward, burden of being the expert, and survival through belonging to the HPS community.

Hermansky-Pudlak syndrome: health care throughout life.

Hermansky-Pudlak syndrome (HPS) is a rare autosomal recessive disease that displays genetic heterogeneity; there are 9 known subtypes. HPS is characterized by oculocutaneous albinism, a platelet storage pool deficiency and resultant bleeding diathesis, and lysosomal accumulation of ceroid lipofuscin. Patients with HPS, specifically those with the genotypes HPS-1, HPS-2, or HPS-4, are predisposed to interstitial lung disease. In addition, some patients with HPS develop granulomatous colitis. Optimal health care requires a thorough knowledge of the unique health risks and functional limitations associated with this syndrome.

Newborn screening for hermansky-pudlak syndrome type 3 in Puerto Rico.

BACKGROUND: Hermansky-Pudlak syndrome (HPS) is an autosomal recessive disorder characterized by albinism, mucocutaneous bleeding, and storage of ceroid material in macrophages. Patients who are not easily identified by physical characteristics (mostly HPS-3 patients) may have hemorrhagic complications with trauma or surgery. OBJECTIVE: To determine the prevalence of HPS-3 in Puerto Rican newborns using DNA pooling technique. DESIGN/METHODS: Twelve percent of annual Puerto Rican births were tested randomly by polymerase chain reaction for the HPS-3 mutation, using pooled DNA extracted from dried blood samples. RESULTS: HPS-3 mutation was detected in 75 samples. Two newborns were found to be homozygous. Carrier frequency was 1:85 (1.18%). CONCLUSIONS: The HPS-3 carrier frequency found (1.18%) justifies universal newborn screening in Puerto Rico. DNA pooling reduces time and labor in newborn screening thus facilitating early diagnosis and treatment of children with HPS-3 and the provision of genetic counseling to parents and relatives.

Spectrum of fibrosing diffuse parenchymal lung disease.

The interstitial lung diseases are a heterogeneous group of disorders characterized by inflammation and/or fibrosis of the pulmonary interstitium. In 2002, the American Thoracic Society and the European Respiratory Society revised the classification of interstitial lung diseases and introduced the term diffuse parenchymal lung disease. The idiopathic interstitial pneumonias are a subtype of diffuse parenchymal lung disease. The idiopathic interstitial pneumonias are subdivided into usual interstitial pneumonia (with its clinical counterpart idiopathic interstitial pneumonia), nonspecific interstitial pneumonia, cryptogenic organizing pneumonia, acute interstitial pneumonia, desquamative interstitial pneumonia, respiratory bronchiolitis interstitial lung disease, and lymphocytic pneumonia. Sarcoidosis and hypersensitivity pneumonitis are the 2 most common granulomatous diffuse parenchymal lung diseases. Rheumatoid arthritis, systemic sclerosis, and dermatomyositis/polymyositis (causing antisynthetase syndrome) are diffuse parenchymal lung diseases of known association because these conditions are associated with connective tissue disease. Hermansky-Pudlak syndrome is a rare genetic diffuse parenchymal lung disease characterized by the clinical triad of pulmonary disease, oculocutaneous albinism, and bleeding diathesis. This review provides an overview of the chronic fibrosing diffuse parenchymal lung diseases. Its primary objective is to illuminate the clinical challenges encountered by clinicians who manage the diffuse parenchymal lung diseases regularly and to offer potential solutions to those challenges. Treatment for the diffuse parenchymal lung diseases is limited, and for many patients with end-stage disease, lung transplantation remains the best option. Although much has been learned about the diffuse parenchymal lung diseases during the past decade, research in these diseases is urgently needed.

Hermansky-Pudlak syndrome with a novel mutation.

We report a case of Hermansky-Pudlak syndrome (HPS) with a novel mutation in the HPS1 gene. This case showed oculocutaneous albinism and lysosomal ceroid accumulation, however platelet dysfunction was not observed. Histopathological findings of the biopsied lung tissue were compatible with HPS. Sequencing analysis showed the insertion of C in the codon 178 (739 bp) of the HPS1 gene forming a stop codon at codon 181. To the best of our knowledge, this is a novel HPS1 gene mutation.

Mutation of a new gene causes a unique form of Hermansky-Pudlak syndrome in a genetic isolate of central Puerto Rico.

Hermansky-Pudlak syndrome (HPS) is a rare autosomal recessive disorder characterized by oculocutaneous albinism and a storage pool deficiency due to an absence of platelet dense bodies. Lysosomal ceroid lipofuscinosis, pulmonary fibrosis and granulomatous colitis are occasional manifestations of the disease. HPS occurs with a frequency of one in 1800 in north-west Puerto Rico due to a founder effect. Several non-Puerto Rican patients also have mutations in HPS1, which produces a protein of unknown function. Another gene, ADTB3A, causes HPS in the pearl mouse and in two brothers with HPS-2 (refs. 11,12). ADTB3A encodes a coat protein involved in vesicle formation, implicating HPS as a disorder of membrane trafficking. We sought to identify other HPS-causing genes. Using homozygosity mapping on pooled DNA of 6 families from central Puerto Rico, we localized a new HPS susceptibility gene to a 1.6-cM interval on chromosome 3q24. The gene, HPS3, has 17 exons, and a putative 113.7-kD product expected to reveal how new vesicles form in specialized cells. The homozygous, disease-causing mutation is a large deletion and represents the second example of a founder mutation causing HPS on the small island of Puerto Rico. We also present an allele-specific assay for diagnosing individuals heterozygous or homozygous for this mutation.

Defects in the cappuccino (cno) gene on mouse chromosome 5 and human 4p cause Hermansky-Pudlak syndrome by an AP-3-independent mechanism.

Defects in a triad of organelles (melanosomes, platelet granules, and lysosomes) result in albinism, prolonged bleeding, and lysosome abnormalities in Hermansky-Pudlak syndrome (HPS). Defects in HPS1, a protein of unknown function, and in components of the AP-3 complex cause some, but not all, cases of HPS in humans. There have been 15 inherited models of HPS described in the mouse, underscoring its marked genetic heterogeneity. Here we characterize a new spontaneous mutation in the mouse, cappuccino (cno), that maps to mouse chromosome 5 in a region conserved with human 4p15-p16. Melanosomes of cno/cno mice are immature and dramatically decreased in number in the eye and skin, resulting in severe oculocutaneous albinism. Platelet dense body contents (adenosine triphosphate, serotonin) are markedly deficient, leading to defective aggregation and prolonged bleeding. Lysosomal enzyme concentrations are significantly elevated in the kidney and liver. Genetic, immunofluorescence microscopy, and lysosomal protein trafficking studies indicate that the AP-3 complex is intact in cno/cno mice. It was concluded that the cappuccino gene encodes a product involved in an AP-3-independent mechanism critical to the biogenesis of lysosome-related organelles. (Blood. 2000;96:4227-4235)