Sickle cell disease (SCD) is an inherited blood disorder marked by homozygosity of hemoglobin S, which is a defective hemoglobin caused by a missense mutation in the β-globin gene. However, clinical phenotypes of SCD vary among patients. To investigate genetic variants associated with various clinical phenotypes of SCD, we genotyped DNA samples from 520 SCD subjects and used a genome-wide association study (GWAS) approach to identify genetic variants associated with phenotypic features of SCD. For HbF levels, the previously reported 2p16.1 locus (BCL11A) reached genome significance (rs1427407, P = 8.58 × 10-10) in our GWAS as expected. In addition, we found a new genome-wide significance locus at 15q14 (rs8182015, P = 2.07 × 10-8) near gene EMC7. GWAS of acute chest syndrome (ACS) detected a locus (rs79915189, P = 3.70 × 10-8) near gene IDH2 at 15q26.1. The SNP, rs79915189, is also an expression quantitative trait locus (eQTL) of IDH2 in multiple tissues. For vasoocclusive episode (VOE), GWAS detected multiple significant signals at 2p25.1 (rs62118798, P = 4.27 × 10-8), 15q26.1 (rs62020555, P = 2.04 × 10-9) and 15q26.3 (rs117797325, P = 4.63 × 10-8). Our findings provide novel insights into the genetic mechanisms of SCD suggesting that common genetic variants play an important role in the presentation of the clinical phenotypes of patients with SCD.

BACKGROUND: Thalassemia and haemoglobinopathies are relatively common among Malaysians. One of the rare haemoglobinopathies reported is Haemoglobin (Hb) Arya, which occurs due to substitution of aspartic acid at residue 47 of the alpha chain by asparagine. Here, we report the detection of Hb Arya in a Malaysian family, which was detected incidentally during family screening.
METHODS: A 16 years-old girl, clinically asymptomatic was noted to have low mean corpuscular haemoglobin (MCV) with normal Hb level. Hb analysis using capillary electrophoresis (CE) showed reduced Hb A of 76.5%, Hb A2 of 1.6% with presence of small peak at Zone 1 likely A2\'. There was also a small peak noted at Hb D zone and Hb S zones which quantified as 1.5% and 20% respectively. Supplementary test by high performance liquid chromatography (HPLC) showed a prominent peak at D-window (19.6%) and a small peak at S-window (0.6%). DNA analysis revealed a heterozygous state of α2 codon 47 Hb Arya mutation. Subsequent family study showed a similar mutation in the father and sister of the index case.
CONCLUSIONS: Very few reports are available up to date regarding Hb Arya. This report highlights the rare haemoglobinopathy in a Malay family in Malaysia that contributes to the growing literature of this rare haemoglobin variant.

This study examined sickle cell disease (SCD) in Saudi Arabia. A systematic search of relevant databases was conducted to identify studies investigating SCD in the Saudi population. Studies were then screened based on predefined criteria and critically appraised for methodological quality. Data was extracted and synthesized to provide an overall picture of the SCD burden in Saudi Arabia. The most commonly reported complications were vaso-occlusive crises (VOC), acute chest syndrome (ACS), acute painful crisis, splenic sequestration, osteomyelitis, aplastic crisis, hemolytic crisis, serious bacterial infections, chronic vascular occlusion (CVO), depression, sickle cell nephropathy (SCN), obstructive sleep apnea (OSA), and renal complications. Reduced blood levels of antioxidant trace elements (Cu, Zn, and Se) may encourage oxidative stress, which in turn may contribute to the pathophysiology of SCD. Infections and ACS were common among young children (<7 years) while pain attacks were common in older children (>7 years). The high rate of hospitalizations among SCD patients highlights the need for better management strategies. Future research should focus on understanding the underlying causes of SCD complications and developing new ways to control them.

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Hemoglobin D variations are a group of hemoglobinopathies caused by mutations in the genes that control the synthesis of new globin chains. Hemoglobin D-Punjab is the most prevalent but frequently asymptomatic, it can occasionally cause mild to moderate hemolytic anemia, making diagnosis difficult and raising the risk of misdiagnosis. This article discusses a rare instance of a seventeen-year-old male in Sindh, Pakistan with iron deficiency anemia who was later found to have the Punjab variation of the hemoglobin D. The patient had signs of weakness, exhaustion, and shortness of breath, which were initially alleviated by iron supplementation but eventually became refractory. Hemoglobin electrophoresis demonstrated the distinctive hypochromic, microcytic red blood cell shape, and laboratory tests verified the presence of the Hemoglobin D-Punjab feature. The instance emphasizes how crucial it is to distinguish Hemoglobin D-Punjab from other anemias in order to guarantee proper care. This case underscores the importance of recognizing hemoglobin D-Punjab trait, to provide appropriate genetic counseling and ensure the patient\'s well-being. Increased awareness among healthcare professionals regarding the diverse spectrum of hemoglobinopathies is essential for accurate diagnosis and management.

Hemoglobin (Hb) disorders are among the most prevalent inherited diseases. Despite a limited number of involved genes, these conditions represent a broad clinical and prognostic spectrum. The menu of laboratory tests is extensive. From widely available modalities, for example, complete blood count to rather sophisticated molecular technologies, the investigation of Hb disorders recapitulates an increasing complexity of laboratory workup in other medical fields. This review highlights a current state of biochemical and molecular investigation of Hb disorders and offers a glimpse on technologies that are yet to be fully embraced in clinical practice.

BACKGROUND: Hereditary anemias are a group of genetic diseases prevalent worldwide and pose a significant health burden on patients and societies. The clinical phenotype of hereditary anemias varies from compensated hemolysis to life-threatening anemia. They can be roughly categorized into three broad categories: hemoglobinopathies, membranopathies, and enzymopathies. Traditional therapeutic approaches like blood transfusions, iron chelation, and splenectomy are witnessing a paradigm shift with the advent of targeted treatments. However, access to these treatments remains limited due to lacking or imprecise diagnoses. The primary objective of the study is to establish accurate diagnoses for patients with hereditary anemias, enabling optimal management. As a secondary objective, the study aims to enhance our diagnostic capabilities.
RESULTS: The DAHEAN study is a nationwide cohort study that collects advanced phenotypic and genotypic data from patients suspected of having hereditary anemias from all pediatric and hematological departments in Denmark. The study deliberates monthly by a multidisciplinary anemia board involving experts from across Denmark. So far, fifty-seven patients have been thoroughly evaluated, and several have been given diagnoses not before seen in Denmark.
CONCLUSIONS: The DAHEAN study and infrastructure harness recent advancements in diagnostic tools to offer precise diagnoses and improved management strategies for patients with hereditary anemias.

BACKGROUND: Hemoglobinopathies are among the most prevalent inherited disorders globally, with carrier prevalence varying significantly across regions. In Saudi Arabia, high rates of consanguineous marriages amplify the risk of these disorders.
OBJECTIVE: This study aims to assess the burden of hemoglobinopathies by evaluating the prevalence and regional distribution of beta-hemoglobin variants, including rare variants, among couples participating in the national premarital screening program.
METHODS: Data were collected from the premarital genetic screening program and entered into the SEHA platform, covering the 13 administrative regions of Saudi Arabia. Blood samples underwent various screening tests for infectious and genetic diseases. Hemoglobin electrophoresis samples were analyzed using capillary electrophoresis, High-Performance Liquid Chromatography (HPLC), or a combination of both methods.
RESULTS: From 2011 to 2018, 1,871,184 individuals were included in the study, with 49.8% male and 50.2% female. The average age was 30.2 years. Hemoglobin S (HbS) was identified in 88,431 individuals (4.7% of the tested population and 78.5% of abnormal screening results), primarily as a sickle cell trait. β-thalassemia was the second most common disorder, identified in 22,420 individuals (1.2% of the population and 19.9% of hemoglobin disorders). HbC and HbD were each detected in 0.04% of cases, while HbO-Arab was identified in 0.007% and HbG in 0.006%. Hemoglobin E and hemoglobin Lepore were found to be extremely rare.
CONCLUSIONS: The study demonstrates regional variation in the prevalence of hemoglobin genetic variants in Saudi Arabia. To effectively mitigate this risk, it is imperative to strengthen public education and awareness, particularly focusing on genetic screening and counseling.

Fetal hemoglobin (HbF) reactivation expression through CRISPR-Cas9 is a promising strategy for the treatment of sickle cell disease (SCD). Here, we describe a genome editing strategy leading to reactivation of HbF expression by targeting the binding sites (BSs) for the lymphoma-related factor (LRF) repressor in the γ-globin promoters. CRISPR-Cas9 treatment in healthy donor (HD) and patient-derived HSPCs resulted in a high frequency of LRF BS disruption and potent HbF synthesis in their erythroid progeny. LRF BS disruption did not impair HSPC engraftment and differentiation but was more efficient in SCD than in HD cells. However, SCD HSPCs showed a reduced engraftment and a myeloid bias compared with HD cells. We detected off-target activity and chromosomal rearrangements, particularly in SCD samples (likely because of the higher overall editing efficiency) but did not impact the target gene expression and HSPC engraftment and differentiation. Transcriptomic analyses showed that the editing procedure results in the up-regulation of genes involved in DNA damage and inflammatory responses, which was more evident in SCD HSPCs. This study provides evidence of efficacy and safety for an editing strategy based on HbF reactivation and highlights the need of performing safety studies in clinically relevant conditions, i.e., in patient-derived HSPCs.

BACKGROUND: The data to support chronic automated red cell exchange (RCE) in sickle cell disease (SCD) outside of stroke prevention, is limited, especially in adults.
METHODS: A retrospective analysis was conducted of patients with SCD who were referred for chronic RCE at our institution over a 10-year period. Data that were evaluated included patient demographics, referral indications, and procedural details (e.g., vascular access, adverse events, etc.). In a subanalysis, the number of annual acute care encounters during 3 years of chronic RCE was compared with that in the year preceding the first RCE.
RESULTS: A total of 164 patients were referred for chronic RCE: median age was 28 years (interquartile range [IQR] = 22-36) at referral and 60% were female. Seventy (42.6%) were naïve to chronic transfusion (simple or RCE) prior to referral. The leading indications for referral were refractory pain (73/164, 44.5%) and iron overload (57/164, 34.7%). A total of 5090 procedures occurred during the study period (median = 19, IQR = 5-45). Of the 138 patients who had central vascular access, 8 (6%) and 16 (12%) had ≥1 central-line-related thrombosis and/or infection, respectively. Of those who were not RBC alloimmunized at initiation of RCE, 12/105 (11.4%) developed new antibodies during chronic RCE. In those 30 patients who were adherent to therapy for 3 years, there was no significant difference in acute care encounters following initiation of RCE.
CONCLUSIONS: Prospective clinical trials are needed to determine which patients are most likely to benefit from chronic RCE and refine selection accordingly.