Donor-type bone marrow aplasia following hematopoietic stem cell transplantation in a child with a novel SAMD9L variant.

Pathogenic variants in the genes SAMD9 (sterile a-motif domain containing protein - 9) and SAMD9L (SAMD9-like) cause bone marrow failure with characteristic syndromic features. We report a case of a previously healthy, 3-year-old boy with no dysmorphology, who presented with severe aplastic anemia and a novel variant in the SAMD9L gene. His father, elder brother and sister who harbored the same variant were completely healthy. In the absence of a matched unrelated donor, he underwent a stem cell transplant from his sister, a 10/10 match. Almost 2 years later he developed donor type aplasia and succumbed to an invasive fungal infection after a failed haplograft from his mother. This case highlights the pathogenicity of this previously undescribed germline variation of uncertain significance in the SAMD9L gene and the value of comprehensive genetic testing for inherited bone marrow failures even in the absence of a positive family history or characteristic congenital abnormalities.

Assessment of iron overload in a cohort of Sri Lankan patients with transfusion dependent beta thalassaemia and its correlation with pathogenic variants in HBB, HFE, SLC40A1, and TFR2 genes.

BACKGROUND: Iron overload (IO) is a complication in transfusion dependent beta thalassaemia (TDT). Pathogenic variants in genes involving iron metabolism may confer increased risk of IO. The objective of this study was to determine the magnitude of the cardiac and hepatic IO and determine whether pathogenic variants in HFE, SLC40A1 and TFR2 genes increase the risk of IO in a cohort of TDT patients in Sri Lanka. MATERIALS AND METHODS: Fifty-seven (57) patients with TDT were recruited for this study. Serum ferritin was done once in 3 months for a period of one year in all. Those who were ≥ 8 years of age (40 patients) underwent T2* MRI of the liver and heart. Fifty-two (52) patients underwent next generation sequencing (NGS) to identify pathogenic variants in HBB, HFE, SLC40A1 and TFR2 genes. RESULTS: The median age of the patients of this cohort was 10 years. It comprised of 30 (52.6%) boys and 27 (47.4%) girls. The median level of serum ferritin was 2452 ng/dl. Hepatic IO was seen in 37 (92.5%) patients and cardiac IO was seen in 17 (42.5%) patients. There was no statistically significant correlation between serum ferritin and hepatic or cardiac IO. Thirty-two (61.5%), 18 (34.6%), 2 (3.8%) of patients were homozygotes, compound heterozygotes and heterozygotes for pathogenic variants in the HBB gene. Eight (15.4%) and 1 (1.9%) patients were heterozygotes for pathogenic and likely pathogenic variants of HFE genes respectively. There were no pathogenic variants for the TfR2 and SLC40A1 genes. The heterozygotes of the pathogenic variants of the HFE were not at increased risk of IO. CONCLUSIONS: Cardiac T2* MRI helps to detect cardiac IO in asymptomatic patients. It is important to perform hepatic and cardiac T2* MRI to detect IO in patients with TDT. There was no statistically significant correlation between pathogenic variants of HBB and HFE genes with hepatic and cardiac IO in this cohort of patients.

A report of haploidentical allogeneic haematopoietic stem cell transplantation for inherited bone marrow failure in Sri Lanka.

Abstract: Bone marrow failure (BMF) in children can be idiopathic (70-80%) or inherited. Haematopoietic stem cell transplantation (HSCT) is the only cure for both causes. Allogeneic HSCT requires a suitable donor. Many children will not have a HLA matched sibling or unrelated donor. A haploidentical donor is available for all children as eaazch parent will have at minimum a 50% HLA match. This report of a 7-year old girl with BMF treated with a haplo-HSCT, the first in Sri Lanka, highlights the importance of developing a haploidentical HSCT programme as a potential cure for a disease with a dismal outcome.

Effect of Prior Symptomatic Dengue Infection on Dengue Haemorrhagic Fever (DHF) in Children.

Pathogenesis of dengue haemorrhagic fever is not fully understood, but it is thought that there is antibody enhancement during the secondary infection, which causes severe dengue haemorrhagic fever (DHF). Therefore, patients who have DHF should have a documented history of symptomatic dengue infection in the past. A retrospective descriptive-analytical study was conducted at the University Paediatric Unit at Lady Ridgeway Hospital for Children, Colombo, Sri Lanka. All children who had fulfilled the criteria for DHF admitted to the unit from April 2018 to September 2018 were recruited into the study. Relevant data were collected from bed head tickets. One hundred and eighty-four children were included in the final analysis. Thirty-three (17.9%) had a past history of documented symptomatic dengue infection, while 82.1% did not have a documented dengue infection. Twelve patients had dengue shock syndrome, and none of them had previously documented symptomatic dengue fever. Dextran was used in 96 patients in the critical phase. Twelve (42%) patients with past documented symptomatic dengue fever needed dextran while 84 (54.9%) patients without a documented past history of dengue fever needed dextran. In our clinical observation, we noticed that children with DHF mostly did not have a documented symptomatic prior dengue infection, while those with a documented symptomatic prior infection had a milder subsequent illness. In fact, the majority (82.1%) of patients with DHF did not have documented previous symptomatic dengue infection. It was also observed that the clinical course of subsequent dengue infection was less severe in patients with previously documented symptomatic dengue fever. This finding should be further evaluated in a larger scale study minimizing the all-confounding factors. This fact is more important in selecting recipients for vaccines against the dengue virus, which are supposed to produce immunity against the virus without causing the severe disease.

Frontometaphyseal dysplasia 1 in a patient from Sri Lanka.

A Sri Lankan male child with supraorbital hyperostosis, broad nasal bridge, small mandible, severe kyphoscoliosis, distal joint contractures of the hands and long second and third toes is described. A hemizygous pathogenic variant in exon 22 of the filamin A (FLNA) gene [NM_001110556.1: c.3557C>T; which leads to a nonsynonymous substitution of serine by leucine at codon 1186 in the FLNA protein; NP_001104026.1: p.Ser1186Leu] was identified. The clinical features observed in this patient were consistent with the cardinal manifestations seen in frontometaphyseal dysplasia 1 (FMD1). However, characteristic extra skeletal manifestations such as cardiac defects, uropathy, and hearing impairment which have previously been reported in association with this condition were absent in this patient.

ATG vs thiotepa with busulfan and cyclophosphamide in matched-related bone marrow transplantation for thalassemia.

Matched-related bone marrow transplantation (BMT) may cure >80% of low-risk children with severe thalassemia (ST). Very long-term follow-up studies have shown how the standard busulfan-cyclophosphamide (BuCy) regimen may be associated with normalization of health-related quality of life, no second malignancies in the absence of chronic graft-versus-host disease, and fertility preservation in many patients. However, because BuCy may be associated with high rejection rates, some centers incorporate thiotepa (Tt) in busulfan- or treosulfan-based regimens, a combination that may increase the risk of permanent infertility. This study retrospectively compares matched-related BMT outcomes in 2 groups of low-risk ST patients conditioned with either Tt or anti-thymocyte globulin (ATG) in addition to BuCy. A total of 81 consecutive first BMTs were performed in 5 collaborating startup BMT centers in the Indian subcontinent between January 2009 and January 2016; 30 patients were transplanted after conditioning with Tt-BuCy between January 2009 and July 2013, whereas between August 2013 and January 2016, 51 patients received ATG-BuCy. All patients were <15 years and had no hepatomegaly (liver ≤2 cm from costal margin). Actuarial overall survival in the Tt-BuCy and ATG-BuCy groups was 87% and 94% and thalassemia-free survival was 80% and 85% at a median follow-up of 37 and 17 months, respectively, with no significant differences by log-rank statistics. Substituting Tt with ATG in the standard BuCy context seems safe and effective and may decrease transplant-related mortality. Higher fertility rates are expected for patients who received ATG-BuCy.

Thalassaemic osteopathy: a cross-sectional preliminary study from Sri Lanka.

INTRODUCTION: The objectives of this study were to demonstrate the presence of low bone mineral density (BMD) and to examine the association of known risk factors for low BMD in patients with beta thalassaemia major in Sri Lanka. METHOD: Thirty-eight patients were studied. Their examination and laboratory investigation findings were recorded (haematology, biochemistry, hormonal profile, COL1A1 rs1800012G>T genotype, dual energy X-ray absorptiometry (DXA) scanning). RESULTS: Mean age was 10.95 years (range 5-21.4). 20 (52.6%) were male. BMD was low (z score ≤-2.0) in 12 (31.5%). Regression analysis of BMD on known risk factors (age, sex, pubertal stage, ferritin level, average pre-transfusion haemoglobin, serum calcium level and COL1A1 rs1800012G>T genotype) controlling for confounding factors on each comparison, showed that only age was significantly associated with low BMD (p=0.005). CONCLUSIONS: Approximately one-third of patients had a low BMD. Only age was significantly associated with a low BMD.