After an initial Hermansky-Pudlak syndrome clinical diagnosis, molecular testing reveals variants for oculocutaneous albinism type 1B: A case report.

BACKGROUND: Albinism is a heterogeneous condition in which patients present complete absence, reduction, or normal pigmentation in skin, hair and eyes in addition to ocular defects. One of the heterogeneous forms of albinism is observed in Hermansky-Pudlak syndrome (HPS) patients. HPS is characterized by albinism and hemorrhagic diathesis due to the absence of dense bodies in platelets. METHODS: In this report, we describe a case of a pair of Puerto Rican siblings with albinism that were clinically diagnosed with HPS during childhood. Since they did not harbor the founder changes in the HPS1 and HPS3 genes common in Puerto Ricans, as adults they wanted to know the type of albinism they had. We performed exome sequencing, validation by PCR, and cloning of PCR products followed by Sanger sequencing in the family members. RESULTS: We discovered no mutations that could explain an HPS diagnosis. Instead, we found the siblings were compound heterozygotes for 4 variants in the Tyrosinase gene: c.-301C>T, c.140G>A (rs61753180; p.G47D), c.575C>A (rs1042602; p.S192Y), and c.1205G>A (rs1126809; p.R402Q). Our results show that the correct diagnosis for the siblings is OCA1B. CONCLUSION: Our study shows the importance of molecular testing when diagnosing a rare genetic disorder, especially in populations were the disease prevalence is higher.

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.

Bleeding assessment in female patients with the Hermansky-Pudlak syndrome-A case series.

INTRODUCTION: The Hermansky-Pudlak syndrome (HPS) is an autosomal recessive rare disorder characterized by oculocutaneous albinism, bleeding diathesis, chronic granulomatous colitis and/or pulmonary fibrosis. HPS is the most common single-gene disorder in Puerto Rico with a prevalence of 1:1,800 in the Northwest of the island. Risk of menorrhagia and post-partum hemorrhage (PPH) in cases of women with HPS have been described in the medical literature, but data regarding comprehensive description of bleeding diathesis remains lacking. For this reason, we aim to identify bleeding events using the International Society on Thrombosis and Hemostasis Bleeding Assessment Tool (ISTH-BAT), a standardized quantitative tool that translates the range of severity of bleeding symptoms into a cumulative bleeding score (BS). OBJECTIVE: To use the ISTH-BAT in HPS in order to describe bleeding symptoms and allow for comparison with other inherited bleeding disorders. METHODS: Puerto Rican females and adult participants with HPS based on genetic linkage were enrolled. The ISTH-BAT was administered and results were identified using descriptive statistical analysis. RESULTS: Questionnaire answers of twelve women with HPS-1 and HPS-3 were evaluated. Participants' mean BS was HPS-1 (11.4) and HPS-3 (8.0) Participants with HPS-1 and HPS-3 reported abnormal bleeding events that presented during dental extractions, menorrhagia, surgical interventions, gastrointestinal, oral cavity and post-partum. Patients with history of pulmonary fibrosis (PF) showed a higher mean bleeding score than those who had no history of PF. CONCLUSIONS: Female patients with HPS type 1 and 3 experienced abnormal bleeding events according to the ISTH-BAT bleeding score. Bleeding medications were inconsistently used and varied independently from healthcare professionals. The benefits of this study were to understand the history of bleeding complications in patients with HPS type 1 and 3 using an international validated system. The results of this study will help design strategies to improve the care we provide to this population.

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.

Pulmonary Fibrosis in Hermansky-Pudlak Syndrome.

Hermansky-Pudlak syndrome (HPS) is a rare autosomal recessive genetic disorder characterized by oculocutaneous albinism and a bleeding diathesis due to platelet dysfunction. More than 50% of cases worldwide are diagnosed on the Caribbean island of Puerto Rico. Genetic testing plays a growing role in diagnosis; however, not all patients with HPS have identified genetic mutations. In Puerto Rico, patients with HPS are often identified shortly after birth by their albinism, although the degree of hypopigmentation is highly variable. Ten subtypes have been described. Patients with HPS-1, HPS-2, and HPS-4 tend to develop pulmonary fibrosis in Puerto Rico; 100% of patients with HPS-1 develop HPS-PF. HPS-PF and idiopathic pulmonary fibrosis are considered similar entities (albeit with distinct causes) because both can show similar histological disease patterns. However, in contrast to idiopathic pulmonary fibrosis, HPS-PF manifests much earlier, often at 30-40 years of age. The progression of HPS-PF is characterized by the development of dyspnea and increasingly debilitating hypoxemia. No therapeutic interventions are currently approved by the U.S. Food and Drug Administration for the treatment of HPS and HPS-PF. However, the approval of two new antifibrotic drugs, pirfenidone and nintedanib, has prompted new interest in identifying drugs capable of reversing or halting the progression of HPS-PF. Thus, lung transplantation remains the only potentially life-prolonging treatment. At present, two clinical trials are recruiting patients with HPS-PF to identify biomarkers for disease progression. Advances in the diagnosis and management of these patients will require the establishment of multidisciplinary centers of excellence staffed by experts in this disease.

Ocular Findings in Patients with the Hermansky-Pudlak Syndrome (Types 1 and 3).

PURPOSE: To describe and compare ocular findings in patients with Hermansky-Pudlak syndrome (HPS) type 1 and 3. METHODS: This is a retrospective case series of 64 patients with HPS from 1999 to 2009 evaluated at an outpatient private ophthalmologic clinic. Patients underwent genetic analysis of selected albinism (Tyrosine and P gene) and HPS genes (HPS-1 and HPS-3) by screening for common mutations and exon sequencing with DNA screening. Descriptive and non-parametric statistical analyses were carried out. RESULTS: Nearly 70% of the patients were homozygous for common Puerto Rican mutations leading to the HPS1 gene (16-BP DUP, 53.6%), while 30% had the 3904-BP DEL HPS3 gene mutation. Best corrected visual acuity (BCVA) was poorer in patients with type 1 HPS than in patients with type 3 HPS (p < 0.001), esotropia was more common among type 1 HPS patients (p < 0.018), while exotropia was more common among patients with type 3 HPS. Total iris transillumination was more common in patients with type 1 HPS and minimal iris transillumination in patients with type 3 HPS (p < 0.001). The maculae were translucent in patients with type 1 HPS, while patients with type 3 HPS had opaque maculae (p < 0.001). CONCLUSIONS: Patients with type 1 HPS had poorer BCVA, increased incidence of esotropia, lighter iris and macular appearance. In contrast, patients with type 3 HPS had more exotropia. In addition, to our knowledge this is the largest series type 3 HPS ever reported.

The Ap3b1 gene regulates the ocular melanosome biogenesis and tyrosinase distribution differently from the Hps1 gene.

Hermansky-Pudlak syndrome (HPS) is an autosomal recessive disorder in humans and mice. The pearl (pe) mouse, a mouse model for the human HPS-2, bears a mutation in Ap3b1 gene. Here we investigated the pigmentation in eyes of pearl (pe) mice, and compared it with our previously published data in pale ear (ep) mice. We revealed that the hypopigmentation in eyes of pearl mice was more severe than pale ear mice, especially in the neural crest-derived tissues. However, the total tyrosinase activity in eyes of pearl mice was stronger than pale ear mice, suggesting that the degradation of aberrantly transported tyrosinase in eyes of pearl mice was weaker than that of pale ear mice. Furthermore, the pigmentation in eyes of mice doubly heterozygous for Hps1 and Ap3b1 genes was similar to the wild-type, while the hypopigmentation in iris of double mutant mice was more severe than either single mutant. Besides, we found several previously reported characters in pale ear mice, including macromelanosomes in the neural crest-derived melanocytes and increased accumulation of lipofuscin in the RPE, were absent in pearl mice. Our study indicates that Ap3b1 gene play distinct roles in melanin production and tyrosinase distribution compared with Hps1 gene.

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.

Novel mutations in the HPS1 gene among Puerto Rican patients.

Hermansky-Pudlak syndrome (HPS) is a disorder of oculocutaneous albinism (OCA) and platelet storage pool deficiency. Eight different disease-causing genes have been identified, whose gene products are thought to be involved in the biogenesis of lysosome-related organelles. HPS type 1 (HPS-1) is the most common HPS subtype in Puerto Rico, with a frequency of 1:1800 in the northwest of the island due to a founder mutation, i.e. a 16-bp duplication in exon 15 of the HPS1 gene (c.1472_1487dup16; p.H497QfsX90). We identified three Puerto Rican HPS-1 patients who carried compound heterozygous HPS1 mutations. One patient was heterozygous for c.937G>A, causing a missense mutation (p.G313S) at the 3 splice junction of exon 10. This mutation resulted in activation of a cryptic intronic splice site causing an aberrantly spliced HPS1 mRNA that included 144-bp of intronic sequence, producing 11 novel amino acids followed by a stop codon. The other two patients were heterozygous for the previously reported c.972delC in HPS1, resulting in a frameshift and a premature stop codon (p.M325WfsX6). These findings indicate that, among Puerto Ricans, other HPS1 mutations apart from the 16-bp duplication should be considered in the analysis of this population.

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.

[Familial pulmonary fibrosis in 2 Mexican sisters with Hermansky-Pudlak syndrome]. / Fibrosis pulmonar familiar en 2 hermanas mexicanas con síndrome de Hermansky-Pudlak.

Hermansky-Pudlak syndrome is an autosomal recessive disorder commonly found in individuals of Puerto Rican ancestry. We present 2 cases of familial pulmonary fibrosis in 2 Mexican sisters with Hermansky-Pudlak syndrome. Pulmonary fibrosis was biopsy-proven in 1 of the patients. This report shows that Hermansky-Pudlak syndrome may occur in individuals of Mexican ancestry.

Hermansky Pudlak syndrome: an unusual form of procto-colitis.

Hermansky-Pudlak syndrome (HPS) is a rare autosomal recessive disorder consisting of oculocutaneous albinism, platelet dysfunction and systemic complications associated with lipofuscin deposition in the reticuloendothelial system. HPS has been associated with a granulomatous enterocolitis with pathologic features suggestive of Crohn's disease. It remains uncertain if HPS represents a truly distinct form of granulomatous enterocolitis. We report a series of two patients with HPS treated in Puerto Rico, and the results from medical and surgical intervention for gastrointestinal disease. Our experience with HPS patients has shown the difficult management of perineal disease similar in the management of Crohn's. However, complications from the bleeding diathesis necessitate caution during surgery and potential anesthesia complications. Furthermore, avoidance of a perineal wound is preferred, and when possible, ileostomies have fewer complications than colostomies as they do not involve the small bowel.

Hermansky Pudlak syndrome: an unusual form of procto-colitis

Hermansky-Pudlak syndrome (HPS) is a rare autosomal recessive disorder consisting of oculocutaneous albinism, platelet dysfunction and systemic complications associated with lipofuscin deposition in the reticuloendothelial system. HPS has been associated with a granulomatous enterocolitis with pathologic features suggestive of Crohn's disease. It remains uncertain if HPS represents a truly distinct form of granulomatous enterocolitis. We report a series of two patients with HPS treated in Puerto Rico, and the results from medical and surgical intervention for gastrointestinal disease. Our experience with HPS patients has shown the difficult management of perineal disease similar in the management of Crohn's. However, complications from the bleeding diathesis necessitate caution during surgery and potential anesthesia complications. Furthermore, avoidance of a perineal wound is preferred, and when possible, ileostomies have fewer complications than colostomies as they do not involve the small bowel.

Hermansky-Pudlak syndrome: dental management considerations.

Hermansky-Pudlak syndrome (HPS) is an autosomal recessive disorder characterized by oculocutaneous albinism (OCA), platelet dysfunction, and ceroid storage. It is common among the Puerto Rican population and is expected to spread within the United States and other countries. Due to the platelet deficiency, these patients are of major concern to pediatric dentists. The purpose of this article is to explain in detail the characteristic triad of this syndrome and to propose an adequate approach to perform dental treatment, using appropriate protection recommendations for HPS patients. Recommendations for dental treatment are considered. They include the use of: (1) eyeglasses with 99 UV filter to protect them from the unpleasant dental light stimulus; (2) an extra-soft toothbrush and conservative brushing technique; (3) medication with antifibrinolitic agents; and (4) local measures to achieve hemostasis.

Genetic testing for oculocutaneous albinism type 1 and 2 and Hermansky-Pudlak syndrome type 1 and 3 mutations in Puerto Rico.

Hermansky-Pudlak syndrome (HPS) (MIM #203300) is a heterogeneous group of autosomal recessive disorders characterized by oculocutaneous albinism (OCA), bleeding tendency, and lysosomal dysfunction. HPS is very common in Puerto Rico (PR), particularly in the northwest part of the island, with a frequency of approximately 1:1,800. Two HPS genes and mutations have been identified in PR, a 16-base pair (bp) duplication in HPS1 and a 3,904-bp deletion in HPS3. In Puerto Ricans with more typical OCA, the most common mutation of the tyrosinase (TYR) (human tyrosinase (OCA1) gene) gene was G47D. We describe screening 229 Puerto Rican OCA patients for these mutations, and for mutations in the OCA2 gene. We found the HPS1 mutation in 42.8% of cases, the HPS3 deletion in 17%, the TYR G47D mutation in 3.0%, and a 2.4-kb deletion of the OCA2 gene in 1.3%. Among Puerto Rican newborns, the frequency of the HPS1 mutation is highest in northwest PR (1:21; 4.8%) and lower in central PR (1:64; 1.6%). The HPS3 gene deletion is most frequent in central PR (1:32; 3.1%). Our findings provide insights into the genetics of albinism and HPS in PR, and provide the basis for genetic screening for these disorders in this minority population.

Poor response to desmopressin acetate (DDAVP) in children with Hermansky-Pudlak syndrome.

BACKGROUND: Hermansky-Pudlak syndrome (HPS) is a common genetic disorder in Puerto Rico. In children with HPS, bleeding is the most disturbing and incapacitating problem. Desmopressin (1-deamino-8-D-arginine vasopressin, (DDAVP)) has been recommended in the management of bleeding disorders characterized by platelet dysfunction, such as HPS. METHODS: Nineteen pediatric Puerto Rican patients with HPS and prolonged bleeding time (BT) were tested for response to administration of DDAVP. RESULTS: Baseline BT was abnormal in 18 (95%) of the patients. The BT following DDAVP administration improved in two cases (11%): one from 7.2 to 5.6 min and the other from 8 to 6 min (Tables II and III). BT measurements remained very prolonged (>15 min) in 17 (89%) of the patients. Patients with the HPS 1 gene mutation had a statistically significant correlation with the poor response following DDAVP (P = 0.03). CONCLUSIONS: DDAVP seldom improves the BT of Puerto Rican children with HPS. Response to DDAVP should be determined individually and platelet transfusion should remain the treatment of choice for a major bleeding episode or surgical procedure.

Color vision in patients with the Hermansky-Pudlak syndrome.

PURPOSE: To study color vision in patients with oculocutaneous albinism (OCA) METHODS: We evaluated color vision in 42 patients with OCA using the HRR color plates. Sixty seven percent of the patients had the Hermansky-Pudlak syndrome (HPS), diagnosed genetically or clinically. The remaining patients had unknown mutations leading to OCA. RESULTS: 47.6 % of patients of OCA of all types included had a color vision defect. Of these, 55% were female and 45% were male patients. 50% of patients with the HPS (all types) had a color vision deficit. 42.9% of patients with OCA of unknown type had color weakness. 57.1% had normal color vision. CONCLUSIONS: Results suggest that many patients with OCA and the HPS have a mild red-green color perception deficiency that is not a sex linked trait. The prevalence of color vision deficits in our study population increased with decreasing visual acuity.

Color vision in patients with the Hermansky-Pudlak syndrome

PURPOSE: To study color vision in patients with oculocutaneous albinism (OCA) METHODS: We evaluated color vision in 42 patients with OCA using the HRR color plates. Sixty seven percent of the patients had the Hermansky-Pudlak syndrome (HPS), diagnosed genetically or clinically. The remaining patients had unknown mutations leading to OCA. RESULTS: 47.6 of patients of OCA of all types included had a color vision defect. Of these, 55 were female and 45 were male patients. 50 of patients with the HPS (all types) had a color vision deficit. 42.9 of patients with OCA of unknown type had color weakness. 57.1 had normal color vision. CONCLUSIONS: Results suggest that many patients with OCA and the HPS have a mild red-green color perception deficiency that is not a sex linked trait. The prevalence of color vision deficits in our study population increased with decreasing visual acuity