Atypical Neurologic Phenotype and Novel SLC30A10 Mutation in Two Brothers with Hereditary Hypermanganesemia.

Manganese (Mn) is an essential element in trace quantity but large amounts are toxic. A novel hereditary disorder encompassing high blood Mn levels, dystonia, polycythemia, distinctive T1 hyperintense signals in the basal ganglia on magnetic resonance imaging (MRI) brain, and chronic liver disease was recently described. The disorder is caused by mutations in a Mn transporter encoding gene SLC30A10. We are reporting the clinical features of this rare disorder in two Saudi brothers. The older brother presented with progressive gait difficulties, hypotonia, intermittent dystonia, polycythemia, and characteristic T1-hyperintense lesions on MRI brain. SLC30A10 sequencing identified a novel missense mutation. The younger brother was identified in presymptomatic phase on family screening. Chelation therapy with disodium calcium edetate (ethylenediaminetetraacetic acid, EDTA) led to stabilization of gait, reduction in Mn levels, and resolution of polycythemia. We wish to highlight the atypical neurologic presentation, a novel missense mutation, and beneficial effect of EDTA in this rare disease.

The landscape of genetic diseases in Saudi Arabia based on the first 1000 diagnostic panels and exomes.

In this study, we report the experience of the only reference clinical next-generation sequencing lab in Saudi Arabia with the first 1000 families who span a wide-range of suspected Mendelian phenotypes. A total of 1019 tests were performed in the period of March 2016-December 2016 comprising 972 solo (index only), 14 duo (parents or affected siblings only), and 33 trio (index and parents). Multigene panels accounted for 672 tests, while whole exome sequencing (WES) represented the remaining 347 tests. Pathogenic or likely pathogenic variants that explain the clinical indications were identified in 34% (27% in panels and 43% in exomes), spanning 279 genes and including 165 novel variants. While recessive mutations dominated the landscape of solved cases (71% of mutations, and 97% of which are homozygous), a substantial minority (27%) were solved on the basis of dominant mutations. The highly consanguineous nature of the study population also facilitated homozygosity for many private mutations (only 32.5% of the recessive mutations are founder), as well as the first instances of recessive inheritance of previously assumed strictly dominant disorders (involving ITPR1, VAMP1, MCTP2, and TBP). Surprisingly, however, dual molecular diagnosis was only observed in 1.5% of cases. Finally, we have encountered candidate variants in 75 genes (ABHD6, ACY3, ADGRB2, ADGRG7, AGTPBP1, AHNAK2, AKAP6, ASB3, ATXN1L, C17orf62, CABP1, CCDC186, CCP110, CLSTN2, CNTN3, CNTN5, CTNNA2, CWC22, DMAP1, DMKN, DMXL1, DSCAM, DVL2, ECI1, EP400, EPB41L5, FBXL22, GAP43, GEMIN7, GIT1, GRIK4, GRSF1, GTRP1, HID1, IFNL1, KCNC4, LRRC52, MAP7D3, MCTP2, MED26, MPP7, MRPS35, MTDH, MTMR9, NECAP2, NPAT, NRAP, PAX7, PCNX, PLCH2, PLEKHF1, PTPN12, QKI, RILPL2, RIMKLA, RIMS2, RNF213, ROBO1, SEC16A, SIAH1, SIRT2, SLAIN2, SLC22A20, SMDT1, SRRT, SSTR1, ST20, SYT9, TSPAN6, UBR4, VAMP4, VPS36, WDR59, WDYHV1, and WHSC1) not previously linked to human phenotypes and these are presented to accelerate post-publication matchmaking. Two of these genes were independently mutated in more than one family with similar phenotypes, which substantiates their link to human disease (AKAP6 in intellectual disability and UBR4 in early dementia). If the novel candidate disease genes in this cohort are independently confirmed, the yield of WES will have increased to 83%, which suggests that most "negative" clinical exome tests are unsolved due to interpretation rather than technical limitations.

Syndrome of hepatic cirrhosis, dystonia, polycythemia, and hypermanganesemia caused by mutations in SLC30A10, a manganese transporter in man.

Environmental manganese (Mn) toxicity causes an extrapyramidal, parkinsonian-type movement disorder with characteristic magnetic resonance images of Mn accumulation in the basal ganglia. We have recently reported a suspected autosomal recessively inherited syndrome of hepatic cirrhosis, dystonia, polycythemia, and hypermanganesemia in cases without environmental Mn exposure. Whole-genome mapping of two consanguineous families identified SLC30A10 as the affected gene in this inherited type of hypermanganesemia. This gene was subsequently sequenced in eight families, and homozygous sequence changes were identified in all affected individuals. The function of the wild-type protein and the effect of sequence changes were studied in the manganese-sensitive yeast strain Δpmr1. Expressing human wild-type SLC30A10 in the Δpmr1 yeast strain rescued growth in high Mn conditions, confirming its role in Mn transport. The presence of missense (c.266T>C [p.Leu89Pro]) and nonsense (c.585del [p.Thr196Profs(∗)17]) mutations in SLC30A10 failed to restore Mn resistance. Previously, SLC30A10 had been presumed to be a zinc transporter. However, this work has confirmed that SLC30A10 functions as a Mn transporter in humans that, when defective, causes Mn accumulation in liver and brain. This is an important step toward understanding Mn transport and its role in neurodegenerative processes.

Clinical profile and treatment of infantile spasms using vigabatrin and ACTH--a developing country perspective.

BACKGROUND: Infantile spasms represent a serious epileptic syndrome that occurs in the early infantile age. ACTH and Vigabatrin are actively investigated drugs in its treatment. This study describes the comparison of their efficacy in a large series of patients with infantile spasms from Pakistan. METHODS: All patients with infantile spasms who presented to Aga Khan University Hospital, Karachi, Pakistan from January, 2006 to April, 2008 were included in this study. Inclusion criteria were clinical symptoms of infantile spasms, hypsarrythmia or modified hyparrythmia on electroencephalography, at least six months of follow-up period and receipt of any of the two drugs mentioned above. The type of drug distribution was random according to the availability, cost and ease of administration. RESULTS: Fifty six cases fulfilled the inclusion criteria. 62.5% were males. Mean age at onset of seizures was 5 +/- 1.4 months. Fifty two (92.8%) patients demonstrated hypsarrythmia on electroencephalography. 64.3% cases were identified as symptomatic while 19.6% were cryptogenic and 16.1% were idiopathic. Eighteen patients received ACTH while 38 patients received Vigabatrin as first line therapy. Initial response to first line therapy was similar (50% for ACTH and 55.3% for Vigabatrin). Overall, the symptomatic and idiopathic groups responded better to Vigabatrin. The relapse rate was higher for ACTH as compared to Vigabatrin (55.5% vs. 33.3%) when considering the first line therapy. Four patients evolved to Lennox-Gastaut variant; all of these patients had initially received Vigabatrin and then ACTH. CONCLUSION: Vigabatrin and ACTH showed no significant difference in the initial treatment of infantile spasms. However, patients receiving ACTH were 1.2 times more likely to relapse as compared to the patients receiving Vigabatrin when considering monotherapy. We suggest that Vigabatrin should be the initial drug of choice in patients presenting with infantile spasms. However, larger studies from developing countries are required to validate the therapeutic trends observed in this study.

Frequency of intestinal parasitic infestation in children of 5-12 years of age in Abbottabad.

BACKGROUND: Worm infestation is a major problem in children from developing countries due to bad hygienic conditions. It produces nutritional deficiencies and anaemia in children, especially when hookworm infestation is present. METHODS: This cross-sectional study deals with investigation of the frequency of intestinal parasitic infestation in children between the ages 5-12 years. A total of 283 subjects were tested and screened for different intestinal parasites at of Department of Physiology, Ayub Medical College, Abbottabad. Negative cases were re-examined and if found free of intestinal pathogenic parasites were labelled as negative. RESULTS: Of the 283 children examined, 230 tested positive for various intestinal parasites. The frequency of helminthic infestation was found to be above 81%. There were 8 different species of helminths and protozoa found in the specimens. By far the highest frequency of 48% was noted for Ascaris lumbricoides while 6.9% (16 cases) of the specimens examined had mixed infestation. The mean Haemoglobin (Hb) level was found to be 9.82 g/dl in males and 9.0 g/dl in females. Virtually no Hookworm infestation was found which may be the reason of not so low Hb level of the subjects. CONCLUSIONS: A very high percentage (81%) of children from suburbs of Abbottabad have intestinal worm infestation and majority of them (48% of positive cases) have Ascaris lumbricoides. Children were not very severely anaemic because of virtually no hook worm cases.

Cerebral Sinus Venous Thrombosis due to Asparaginase Therapy.

We report a 9-year-old boy with acute lymphoblastic leukemia (ALL) in high-risk group who suffered from left sided focal seizures and ipsilateral hemiparesis during his induction with Asparaginase chemotherapy. Superior sagittal sinus thrombosis and right frontal hemorrhage were demonstrated on brain magnetic resonance imaging (MRI) scans . Anticoagulation was initiated with unfractionated heparin and switched to low molecular weight heparin after 3 weeks and continued for 6 months. At one-year followup, he had complete response to chemotherapy for ALL, with residual mild left hemiparesis, and his MRI scans revealed recanalized venous sinuses. The case highlights the importance of considering cerebral venous thrombosis as a complication of Asparaginase therapy.