Inherited Metabolic Disorders in Adults: A view from Saudi Arabia

The incidence of inherited metabolic disorders (IMD) in Saudi Arabia is one of the highest in the world. Early diagnosis and advances in the treatment of these diseases have led to improved survival of these patients resulting in a rapidly growing number of adults with IMD. This is the first report from a single tertiary care center, on the experience of managing a large cohort of adult patients with a wide range of IMD. We describe the common IMD seen in adult patients in Saudi Arabia, highlighting the variations from the Caucasian populations, and unique challenges in providing care to these adults. We mention the pitfalls causing the delay in the diagnosis particularly in cases of late-onset IMD in adults. We also discuss some unusual complications seen in adult patients during the course of their disease. We describe the role of genetic prevention services in Saudi Arabia and the importance of research in this field.     

Successful Outcome in Patients with Fanconi Anemia Undergoing T Cell-Replete Mismatched Related Donor Hematopoietic Cell Transplantation Using Reduced-Dose Cyclophosphamide Post-Transplantation

Allogeneic hematopoietic cell transplantation (HCT) has been shown to restore normal hematopoiesis in patients with Fanconi anemia (FA), with excellent results in matched related donor HCT. Outcomes of alternative donor HCT are less favorable, however. In patients without FA, several reports have documented stable engraftment and/or a low risk of graft-versus-host disease (GVHD) using unmanipulated HLA-mismatched related donors and post-HCT cyclophosphamide (PT-CY) for GVHD prophylaxis. Data on the use of this approach in patients with FA are scarce, and thus we launched a study of HLA-mismatched related donor HCT in these patient. Here we report our findings in 19 patients. The conditioning was fludarabine 30 mg/m²/day for 5 days, antithymocyte globulin 5 mg/kg/day for 4 days, and total body irradiation (total dose, 200 cGy). GVHD prophylaxis was cyclosporine and mycophenolate and reduced doses of PT-CY, 25 mg/kg, on days +3 and +5. All patients exhibited absolute neutrophil count recovery. Grade III-IV acute GVHD occurred in 3 patients, and chronic GVHD occurred in 1 patient. At a mean follow-up of 38.3 ± 5.8 months, the 5-year probability of overall survival for our patients was 89.2% ± 7.2%. The regimen was well tolerated; hemorrhagic cystitis occurred in 7 patients, and severe mucositis occurred in 5 patients. There were 2 deaths; the primary cause of death was severe GVHD in 1 patient and leukemia recurrence in the other. We conclude that in patients with FA lacking a matched related donor, the use of mismatched related HCT with low-dose PT-CY is a viable option; it is well tolerated, with a high rate of engraftment and an acceptable incidence of GVHD.     

Analysis of CCR5 gene polymorphisms in 321 healthy Saudis using Next Generation Sequencing

Aims

To investigate the extent of CCR5 polymorphism in the healthy Saudi population.

The pathogenesis of experimental Haemonchus longistipes infection in goats

Goats are highly susceptible to Haemonchus longistipes and could therefore serve as an inexpensive model to study camel haemonchosis. The course of the disease in goats is similar to that in camels and to H. contortus infection in sheep and goats. Unlike the age-dependency of camel haemonchosis, however, the severity of H. longistipes infection in goats is dose-dependent and varies from mild to hyperacute.     

Clinical features,molecular characteristics,and treatments of a Chinese girl with sitosterolemia: A case report and literature review

Sitosterolemia is a rare autosomal recessive disease characterized by a significant increase in blood plant sterol levels. Clinical manifestations usually include xanthomas, hypercholesterolemia,premature atherosclerosis and hematological abnormalities. We report here a sitosterolemia patient who presented with multiple xanthomas and profound hypercholesterolemia since 3 years old. The girl was mistreated as familial hypercholesterolemia for 6 years until correct diagnosis was made by detecting serum plant cholesterol levels. Sequence analysis revealed compound heterozygous mutations in ABCG5 gene, including the previously reported mutation c.904+1G＞A and a novel missense mutation c.1528C＞A. Although cholestyramine therapy reduced cholesterol level in association with marked regress of the xanthomas, serum plant sterol levels still remain high. Our study suggests that patients develop severe hypercholesterolemia and xanthomas at early age should be suspected of sitosterolemia. In addition, we also describe a novel missense mutation in exon 11 of the ABCG5 gene, which enriches the genetic mutation spectrum of sitosterolemia.     

Disturbed phospholipid metabolism in serine biosynthesis defects revealed by metabolomic profiling

Serine biosynthesis defects are autosomal recessive metabolic disorders resulting from the deficiency of any of the three enzymes involved in de novo serine biosynthesis, specifically phosphoglycerate dehydrogenase (PGDH), phosphoserine aminotransferase (PSAT), and phosphoserine phosphatase (PSP). In this study, we performed metabolomic profiling on 4 children with serine biosynthesis defects; 3 with PGDH deficiency and 1 with PSAT deficiency. The evaluations were performed at baseline and with serine and glycine supplementation. Metabolomic profiling performed at baseline showed low phospholipid species, including glycerophosphocholine, glycerophosphoethanolamine, and sphingomyelin. All children had low serine and glycine as expected. Low glycerophosphocholine compounds were found in 4 children, low glycerophosphoethanolamine compounds in 3 children, and low sphingomyelin species in 2 children. Metabolic profiling with serine and glycine supplementation showed normalization of most of the low phospholipid compounds in the 4 children. Phospholipids are the major component of plasma and intracellular membranes, and phosphatidylcholine is the most abundant phospholipid of all mammalian cell types and subcellular organelles. Phosphatidylcholine is of particular importance for the nervous system, where it is essential for neuronal differentiation. The observed low phosphatidylcholine species in children with serine biosynthesis defects that improved after serine supplementation, supports the role of serine as a significant precursor for phosphatidylcholine. The vital role that phosphatidylcholine has during neuronal differentiation and the pronounced neurological manifestations in serine biosynthesis defects suggest that phosphatidylcholine deficiency occurring secondary to serine deficiency may have a significant contribution to the development of the neurological manifestations in individuals with serine biosynthesis defects.     

Decreased expression of lncRNA loc285194 as an independent prognostic marker in cancer: A systematic review and meta-analysis

BackgroundSeveral studies have indicated that lncRNA loc285194 is aberrantly expressed in many types of cancer. This meta-analysis was performed to elucidate the potential role of lncRNA loc285194 as a prognostic marker in malignant tumors.MethodsAn electronic search of PubMed, Medline, Embase, and Web of Science was performed to identify all eligible papers related to the prognostic impact of lncRNA loc285194 expression in cancer. Hazard ratios (HR) and 95% confidence intervals (CI) were extracted from the included studies to explore the association between lncRNA loc285194 expression and patient overall and disease-free survival (OS & DFS). The odds ratios (ORs) were also calculated to assess the association between lncRNA loc285194 expression and clinicopathological parameters.ResultsA total of 14 eligible articles with 1215 patients were included in this meta-analysis. Meta-results revealed that low expression of lncRNA loc285194 was significantly correlated with poorer overall survival (OS; HR = 2.34; 95% CI, 1.78–3.06; P < 0.001) and disease-free survival (DFS; HR = 2.66; 95% CI, 1.95–3.64; P = 0.001) rates in cancer patients. Low lncRNA loc285194 expression was also found to be significantly associated with lymph node metastasis (LNM; OR = 2.17; 95% CI, 1.23–3.83; P = 0.007), and distant metastasis (DM; OR = 2.49; 95% CI, 1.26–4.91; P = 0.009).ConclusionsThis study demonstrated that decreased level of lncRNA loc285194 was associated with poor clinical outcomes for patients with different types of cancer, supporting a promising potential biomarker for prognosis and metastasis in human cancers.     

Biallelic mutations in AP3D1 cause Hermansky-Pudlak syndrome type 10 associated with immunodeficiency and seizure disorder

Several types of Hermansky-Pudlak syndromes (HPS) represent a group of immunodeficiency syndromes that feature both leukocyte defects with partial albinism of hair, skin, and eyes. These conditions share defects in genes that encode proteins involved in the biogenesis, function, and trafficking of secretory lysosomes. Mutations in AP3D1 which encode the main subunit AP-3(δ) were recently reported on one individual and led to Hermansky-Pudlak Syndrome type 10 (HPS10; OMIM 617050). HPS10 is a severe condition that manifests with symptoms of oculocutaneous albinism, neurodevelopmental delays, platelet dysfunction, and immunodeficiency.Herein we report on three affected individuals who presented with severe seizures, developmental delay, albinism, and immunodeficiency. Whole exome sequencing identified homozygosity for a deleterious sequence variant of high impact in AP3D1, c.1978delG, predicting p.Ala660Argfs*54 (NM_001261826.3).We further demonstrated an abnormal storage pathway in the platelets. The current study represents a second confirmation report and implicates AP3D1 mutations as a cause of Hermansky-Pudlak Syndrome type 10.     

Cytogenetic follow-up of patients with nonlymphocytic leukemia. II. Acute nonlymphocytic leukemia

Bone marrow (BM) karyotypes of 86 patients with acute nonlymphocytic leukemia (ANLL) were studied at the time of diagnosis; 39 of them (45%) were normally diploid and 47 (55%) showed acquired abnormalities. The median survival was no longer in the diploid group than in the aneuploid one. Nonrandom aberrations were often found: trisomy 8 (15 times), monosomy 7 (7 times), and t(8;21) (7 times). Two patients with acute promyelocytic leukemia presented with the t(15;17) in BM cells. Serial cytogenetic studies performed in 17 cases showed that karyotypic evolution closely followed the clinical evolution. Complete remission, obtained in 10 cases, was characterized by BM metaphases with a normal karyotype. Relapse after a period of complete remission was documented four times; the BM metaphases then showed the original abnormal karyotype with additional changes that, in three cases, were limited to a new structural aberration.     

Cytogenetic findings in chronic myeloid leukemia (CML); evaluation of karyotype,blast morphology,and survival in the acute phase

Cytogenetic data on a series of 68 patients with chronic myeloid leukemia (CML) are presented, with emphasis on chromosomal findings in 19 patients who either transformed from a chronic to an acute phase (12 cases) or presented in an acute phase (7 cases). Correlation of chromosome patterns, blast morphology, and survival was attempted, following the aims and recommendations of the First International Workshop in Leukemia (Cytogenet Cell Genet (1977): 19, 321). A Philadelphia (Ph¹) chromosome was detected in 61 of 68 patients (90%) and identified by banding in 40 cases; 39 patients had the usual (9;22) translocation and one patient showed an unusual (17;22) Ph¹ translocation. Clonal abnormalities in addition to the Ph¹ were found in 9% of chronic patients whereas 79% of acute patients showed karyotypic clonal evolution. The three most frequently observed patterns of clonal evolution were trisomy 8, two Ph¹ chromosomes and an isochromosome 17 (i(17q)). Two Ph¹ chromosomes were observed in both chronic and acute cases, but in this series, trisomy 8 and i(17q) were detected only in acute patients. Detection of clonal evolution is generally indicative of an accelerated phase in the majority of cases and the development of an i(17q) clone is particularly ominous. After transformation, no obvious correlation between the pattern of clonal evolution, blast morphology, or survival was found.     

Cytogenetic follow-up of patients with nonlymphocytic leukemia I. Philadelphia chromosome-positive chronic myeloid leukemia

Chromosomes of blood and bone marrow cells were studied in 53 patients with Philadelphia chromosome (Ph¹)-positive chronic myeloid leukemia (CML). Fifty patients presented with t(9;22) and three with variant translocations: t(17p+;22q?); t(17q+;22q?), and t(1;9;22). Serial studies were carried out in 27 patients during both the chronic and the blastic phase of the disease. Five patients in the chronic phase developed cytogenetic changes in addition to the Ph¹. In two of these cases the changes preceded a transformation into acute leukemia, but in three cases no acceleration of the disease has occurred 1 to 4 years after the emergence of the subclones. Blastic transformation occurred in 15 instances; 11 of these patients acquired additional nonrandom chromosomal changes: trisomy 8 (9 times), i(17q) (4 times), trisomy 17 (2 times), trisomy 19 (7 times), and duplication of the 22q? (6 times). Clonal evolution was found in eight cases, either at the onset of blastic transformation or later in follow-up cultures. The differences between karyotypic evolution during the chronic and blastic phases of CML are discussed, together with their prognostic significance.     

Preparation of protein A-peroxidase monoconjugate using a heterobifunctional reagent, and its use in enzyme immunoassays

Protein A-peroxidase monoconjugate was prepared in solution using a heterobifunctional reagent, N-succinimidyl-3-(2-pyridyldithio)-propionate. The yield of the monoconjugate was much higher than that obtained with current methods. An immunoassay method was developed in which protein A-peroxidase monoconjugate served as a universal tool. Protein A-peroxidase monoconjugate was taken up by IgG molecules immobilized on an excess of solid phase antigen. The ability of free antigen to inhibit the binding of antibody, measured as inhibition of conjugate up take, served as the basis for quantification in the assay. The method was applied to human chorionic gonadotropin (HCG) and human IgG. Optimal assay conditions were developed and it was found that as little as 1 ng of HCG/ml and 2 ng of IgG/ml could be detected. The method is of comparable sensitivity to other available immunoassay methods and gives accurate, reproducible results.     

The incidence, type, and subsequent evolution of 14 variant Ph1 translocations in 180 South African patients with Ph1-positive chronic myeloid leukemia

A Philadelphia (Ph1) chromosome translocation was found in 180 of 198 cases of chronic myeloid leukemia (CML). A standard t(9;22) was present in 166 patients, 83 of whom were black, 79 white, and 4 of "mixed" ancestry; whereas a variant Ph1 translocation was detected in 14 patients (7.8%), 11 of whom were black and only 3 white. There was a higher frequency of a variant Ph1 among black patients compared with whites. The significantly higher frequency of a variant among our patients compared with surveys from elsewhere could be due to differing environmental agents. Simple variants were detected in four patients. Complex variants were found in eight cases; in one of these patients, only chromosomes #9 and #22 were involved, but a complex rearrangement of chromosome #9 had occurred. A "masked" Ph1 translocation was detected in two cases, both of which showed monosomy #22 because the Ph1 chromosome was incorporated or interchanged with chromosome #9. Karyotypic evolution of the Ph1-positive cell line was observed more frequently in the variant group (71.4%) than the standard group (29.5%). This difference was significant (p less than 0.005). There was no difference in the type of clonal changes seen in standard and variant groups. The majority of clonal changes were observed during the acute stage in both groups. In the variant group, there was no obvious correlation between the type of variant, type of clonal change, blast morphology, or survival. Their initial survival pattern resembled that of Ph1-negative cases, but those patients who survived longer than 1 year showed a survival trend similar to standard Ph1-positive cases. Possible explanations for the specificity of chromosome #22 involvement and the constancy of the 22q11 breakpoint in all these variant translocations are discussed.     

12q14 microdeletion syndrome: A family with short stature and Silver-Russell syndrome (SRS)-like phenotype and review of the literature

We report here on the first family with short stature and Silver-Russell-like phenotype due to a microdeletion in 12q14.3. The Netchine-Harbison clinical scoring system was used for the clinical diagnosis of Silver-Russell syndrome (SRS). The three affected first-degree relatives (index patient, mother and brother) presented with prenatal and postnatal growth retardation, feeding difficulties, a prominent forehead and a failure to thrive, but did not show relative macrocephaly. In addition, our index patient showed dysmorphic facial features, periodically increased sweating, and scoliosis. Learning problems and cardiac arrhythmia presented as additional features of her brother. Using high-resolution array-CGH, heterozygosity for a 1.67?Mb deletion in 12q14.3 was detected in the index patient. The heterozygous loss was confirmed by MLPA in the index patient and the other two affected family members. The deletion includes the genes HMGA2, LLPH, TMBIM4, IRAK3, HELB, GRIP1, and the pseudogene RPSAP52. We conclude from these results and from the data of other patients reported in the literature that haploinsufficiency of HMGA2 leads to the short stature in this family.