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2. Mutation-specific pathophysiological mechanisms define different neurodevelopmental disorders associated with SATB1 dysfunction

Author

Hoed, J. den, Boer, E. de, Voisin, N., Dingemans, A.J.M., Guex, N., Wiel, L.J.M. van de, Nellaker, C., Amudhavalli, S.M., Banka, S., Bena, F.S., Ben-Zeev, B., Bonagura, V.R., Bruel, A.L., Brunet, T., Brunner, H.G., Chew, H.B., Chrast, J., Cimbalistienė, L., Coon, H., Délot, E.C., Démurger, F., Denommé-Pichon, A.S., Depienne, C., Donnai, D., Dyment, D.A., Elpeleg, O., Faivre, L., Gilissen, C.F., Granger, L., Haber, B., Hachiya, Y., Abedi, Y.H., Hanebeck, J., Hehir-Kwa, J.Y., Horist, B., Itai, T., Jackson, A., Jewell, R., Jones, K.L., Joss, S., Kashii, H., Kato, M., Kattentidt-Mouravieva, A.A., Kok, F., Kotzaeridou, U., Krishnamurthy, V., Kučinskas, V., Kuechler, A., Lavillaureix, A., Liu, P, Manwaring, L., Matsumoto, N., Mazel, B., McWalter, K., Meiner, V., Mikati, M.A., Miyatake, S., Mizuguchi, T., Moey, L.H., Mohammed, S, Mor-Shaked, H., Mountford, H., Newbury-Ecob, R., Odent, S., Orec, L., Osmond, M., Palculict, T.B., Parker, M., Petersen, A.K., Pfundt, R.P., Preikšaitienė, E., Radtke, K., Ranza, E., Rosenfeld, J.A., Santiago-Sim, T., Schwager, C., Sinnema, M., Snijders Blok, L., Spillmann, R.C., Stegmann, A.P.A., Thiffault, I., Tran, L., Vaknin-Dembinsky, A., Vedovato-Dos-Santos, J.H., Schrier Vergano, S.A., Vilain, E., Vitobello, A., Wagner, M., Waheeb, A., Willing, M., Zuccarelli, B., Kini, U., Newbury, D.F., Kleefstra, T., Reymond, A., Fisher, S.E., Vissers, L.E.L.M., Hoed, J. den, Boer, E. de, Voisin, N., Dingemans, A.J.M., Guex, N., Wiel, L.J.M. van de, Nellaker, C., Amudhavalli, S.M., Banka, S., Bena, F.S., Ben-Zeev, B., Bonagura, V.R., Bruel, A.L., Brunet, T., Brunner, H.G., Chew, H.B., Chrast, J., Cimbalistienė, L., Coon, H., Délot, E.C., Démurger, F., Denommé-Pichon, A.S., Depienne, C., Donnai, D., Dyment, D.A., Elpeleg, O., Faivre, L., Gilissen, C.F., Granger, L., Haber, B., Hachiya, Y., Abedi, Y.H., Hanebeck, J., Hehir-Kwa, J.Y., Horist, B., Itai, T., Jackson, A., Jewell, R., Jones, K.L., Joss, S., Kashii, H., Kato, M., Kattentidt-Mouravieva, A.A., Kok, F., Kotzaeridou, U., Krishnamurthy, V., Kučinskas, V., Kuechler, A., Lavillaureix, A., Liu, P, Manwaring, L., Matsumoto, N., Mazel, B., McWalter, K., Meiner, V., Mikati, M.A., Miyatake, S., Mizuguchi, T., Moey, L.H., Mohammed, S, Mor-Shaked, H., Mountford, H., Newbury-Ecob, R., Odent, S., Orec, L., Osmond, M., Palculict, T.B., Parker, M., Petersen, A.K., Pfundt, R.P., Preikšaitienė, E., Radtke, K., Ranza, E., Rosenfeld, J.A., Santiago-Sim, T., Schwager, C., Sinnema, M., Snijders Blok, L., Spillmann, R.C., Stegmann, A.P.A., Thiffault, I., Tran, L., Vaknin-Dembinsky, A., Vedovato-Dos-Santos, J.H., Schrier Vergano, S.A., Vilain, E., Vitobello, A., Wagner, M., Waheeb, A., Willing, M., Zuccarelli, B., Kini, U., Newbury, D.F., Kleefstra, T., Reymond, A., Fisher, S.E., and Vissers, L.E.L.M.

Abstract

Contains fulltext : 231687.pdf (Publisher’s version ) (Closed access), Whereas large-scale statistical analyses can robustly identify disease-gene relationships, they do not accurately capture genotype-phenotype correlations or disease mechanisms. We use multiple lines of independent evidence to show that different variant types in a single gene, SATB1, cause clinically overlapping but distinct neurodevelopmental disorders. Clinical evaluation of 42 individuals carrying SATB1 variants identified overt genotype-phenotype relationships, associated with different pathophysiological mechanisms, established by functional assays. Missense variants in the CUT1 and CUT2 DNA-binding domains result in stronger chromatin binding, increased transcriptional repression, and a severe phenotype. In contrast, variants predicted to result in haploinsufficiency are associated with a milder clinical presentation. A similarly mild phenotype is observed for individuals with premature protein truncating variants that escape nonsense-mediated decay, which are transcriptionally active but mislocalized in the cell. Our results suggest that in-depth mutation-specific genotype-phenotype studies are essential to capture full disease complexity and to explain phenotypic variability.

Published
2021

7. Neonatal nonepileptic myoclonus is a prominent clinical feature of KCNQ2 gain-of-function variants R201C and R201H

Author

Mulkey, S.B., Ben-Zeev, B., Nicolai, J., Carroll, J.L., Gronborg, S., Jiang, Y.H., Joshi, N., Kelly, M., Koolen, D.A., Mikati, M.A., Park, K., Pearl, P.L., Scheffer, I.E., Spillmann, R.C., Taglialatela, M., Vieker, S., Weckhuysen, S., Cooper, E.C., Cilio, M.R., Mulkey, S.B., Ben-Zeev, B., Nicolai, J., Carroll, J.L., Gronborg, S., Jiang, Y.H., Joshi, N., Kelly, M., Koolen, D.A., Mikati, M.A., Park, K., Pearl, P.L., Scheffer, I.E., Spillmann, R.C., Taglialatela, M., Vieker, S., Weckhuysen, S., Cooper, E.C., and Cilio, M.R.

Abstract

Item does not contain fulltext, OBJECTIVE: To analyze whether KCNQ2 R201C and R201H variants, which show atypical gain-of-function electrophysiologic properties in vitro, have a distinct clinical presentation and outcome. METHODS: Ten children with heterozygous, de novo KCNQ2 R201C or R201H variants were identified worldwide, using an institutional review board (IRB)-approved KCNQ2 patient registry and database. We reviewed medical records and, where possible, interviewed parents and treating physicians using a structured, detailed phenotype inventory focusing on the neonatal presentation and subsequent course. RESULTS: Nine patients had encephalopathy from birth and presented with prominent startle-like myoclonus, which could be triggered by sound or touch. In seven patients, electroencephalography (EEG) was performed in the neonatal period and showed a burst-suppression pattern. However, myoclonus did not have an EEG correlate. In many patients the paroxysmal movements were misdiagnosed as seizures. Seven patients developed epileptic spasms in infancy. In all patients, EEG showed a slow background and multifocal epileptiform discharges later in life. Other prominent features included respiratory dysfunction (perinatal respiratory failure and/or chronic hypoventilation), hypomyelination, reduced brain volume, and profound developmental delay. One patient had a later onset, and sequencing indicated that a low abundance (~20%) R201C variant had arisen by postzygotic mosaicism. SIGNIFICANCE: Heterozygous KCNQ2 R201C and R201H gain-of-function variants present with profound neonatal encephalopathy in the absence of neonatal seizures. Neonates present with nonepileptic myoclonus that is often misdiagnosed and treated as seizures. Prognosis is poor. This clinical presentation is distinct from the phenotype associated with loss-of-function variants, supporting the value of in vitro functional screening. These findings suggest that gain-of-function and loss-of-function variants need different targeted th

Published
2017

8. Distinct neurological disorders with ATP1A3 mutations

Author

Heinzen, E.L., Arzimanoglou, A., Brashear, A., Clapcote, S.J., Gurrieri, F., Goldstein, D.B., Johannesson, S.H., Mikati, M.A., Neville, B., Nicole, S., Ozelius, L.J., Poulsen, H., Schyns, T., Sweadner, K.J., Maagdenberg, A. van den, Vilsen, B., and ATP1A3 Working Grp

Published
2014

9. Functional genome-wide siRNA screen identifies KIAA0586 as mutated in Joubert syndrome

Author

Roosing, S., Hofree, M., Kim, S., Scott, E., Copeland, B., Romani, M., Silhavy, J.L., Rosti, R.O., Schroth, J., Mazza, T., Miccinilli, E., Zaki, M.S., Swoboda, K.J., Milisa-Drautz, J., Dobyns, W.B., Mikati, M.A., Incecik, F., Azam, M., Borgatti, R., Romaniello, R., Boustany, R.M., Clericuzio, C.L., D'Arrigo, S., Stromme, P., Boltshauser, E., Stanzial, F., Mirabelli-Badenier, M., Moroni, I., Bertini, E., Emma, F., Steinlin, M., Hildebrandt, F., Johnson, C.A., Freilinger, M., Vaux, K.K., Gabriel, S.B., Aza-Blanc, P., Heynen-Genel, S., Ideker, T., Dynlacht, B.D., Lee, J.E., Valente, E.M., Kim, J., Gleeson, J.G., Roosing, S., Hofree, M., Kim, S., Scott, E., Copeland, B., Romani, M., Silhavy, J.L., Rosti, R.O., Schroth, J., Mazza, T., Miccinilli, E., Zaki, M.S., Swoboda, K.J., Milisa-Drautz, J., Dobyns, W.B., Mikati, M.A., Incecik, F., Azam, M., Borgatti, R., Romaniello, R., Boustany, R.M., Clericuzio, C.L., D'Arrigo, S., Stromme, P., Boltshauser, E., Stanzial, F., Mirabelli-Badenier, M., Moroni, I., Bertini, E., Emma, F., Steinlin, M., Hildebrandt, F., Johnson, C.A., Freilinger, M., Vaux, K.K., Gabriel, S.B., Aza-Blanc, P., Heynen-Genel, S., Ideker, T., Dynlacht, B.D., Lee, J.E., Valente, E.M., Kim, J., and Gleeson, J.G.

Abstract

Contains fulltext : 155320.pdf (publisher's version ) (Open Access), Defective primary ciliogenesis or cilium stability forms the basis of human ciliopathies, including Joubert syndrome (JS), with defective cerebellar vermis development. We performed a high-content genome-wide small interfering RNA (siRNA) screen to identify genes regulating ciliogenesis as candidates for JS. We analyzed results with a supervised-learning approach, using SYSCILIA gold standard, Cildb3.0, a centriole siRNA screen and the GTex project, identifying 591 likely candidates. Intersection of this data with whole exome results from 145 individuals with unexplained JS identified six families with predominantly compound heterozygous mutations in KIAA0586. A c.428del base deletion in 0.1% of the general population was found in trans with a second mutation in an additional set of 9 of 163 unexplained JS patients. KIAA0586 is an orthologue of chick Talpid3, required for ciliogenesis and Sonic hedgehog signaling. Our results uncover a relatively high frequency cause for JS and contribute a list of candidates for future gene discoveries in ciliopathies.

Published
2015

16. Efficacy of gabapentin therapy in children with refractory partial seizures

Author

Khurana, D.S., Riviello, J., Helmers, S., Holmes, G., Anderson, J., and Mikati, M.A.

Abstract

Thirty-two children with refractory partial epilepsy received open-label gabapentin as an additional medication to their antiepileptic drug regimen. Gabapentin was given in a dose ranging from 10 to 50 mg/kg per day (mean dose, 26.7 mg/kg daily). All patients had partial seizures with or without secondary generalization. Compared with baseline, 11 patients (34.4%) had a greater than 50% decrease in seizure frequency, and 4 (12.5%) had a 25% to 50% decrease in seizure frequency. Of the seven children who received the medication for 6 months or longer, two were seizure free and four were almost seizure free (having one seizure every few months). Mean gabapentin concentration was 4.8 @mg/ml, and mean apparent clearance was 372 ml/kg per hour. The major reported side effects were behavioral. These consisted of hyperactivity, irritability, and agitation that occurred in patients with baseline mental retardation with attention deficit. We conclude that gabapentin can be a useful adjunctive medication in the treatment of refractory partial epilepsy in children. (J PEDIATR 1996;128:829-33)

Published
1996
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18. Mutation-specific pathophysiological mechanisms define different neurodevelopmental disorders associated with SATB1 dysfunction

Author

den Hoed, J., de Boer, E., Voisin, N., Dingemans, A.J.M., Guex, N., Wiel, L., Nellaker, C., Amudhavalli, S.M., Banka, S., Bena, F.S., Ben-Zeev, B., Bonagura, V.R., Bruel, A.-L., Brunet, T., Brunner, H.G., Chew, H.B., Chrast, J., Cimbalistienė, L., Coon, H., Délot, E.C., Démurger, F., Denommé-Pichon, A.-S., Depienne, C., Donnai, D., Dyment, D.A., Elpeleg, O., Faivre, L., Gilissen, C., Granger, L., Haber, B., Hachiya, Y., Abedi, Y.H., Hanebeck, J., Hehir-Kwa, J.Y., Horist, B., Itai, T., Jackson, A., Jewell, R., Jones, K.L., Joss, S., Kashii, H., Kato, M., Kattentidt-Mouravieva, A.A., Kok, F., Kotzaeridou, U., Krishnamurthy, V., Kučinskas, V., Kuechler, A., Lavillaureix, A., Liu, P., Manwaring, L., Matsumoto, N., Mazel, B., McWalter, K., Meiner, V., Mikati, M.A., Miyatake, S., Mizuguchi, T., Moey, L.H., Mohammed, S., Mor-Shaked, H., Mountford, H., Newbury-Ecob, R., Odent, S., Orec, L., Osmond, M., Palculict, T.B., Parker, M., Petersen, A., Pfundt, R., Preikšaitienė, E., Radtke, K., Ranza, E., Rosenfeld, J.A., Santiago-Sim, T., Schwager, C., Sinnema, M., Blok, L.S., Spillmann, R.C., Stegmann, A.P.A., Thiffault, I., Tran, L., Vaknin-Dembinsky, A., Vedovato-dos-Santos, J.H., Vergano, S.A., Vilain, E., Vitobello, A., Wagner, M., Waheeb, A., Willing, M., Zuccarelli, B., Kini, U., Newbury, D.F., Kleefstra, T., Reymond, A., Fisher, S.E., Vissers, L.E.L.M., den Hoed, J., de Boer, E., Voisin, N., Dingemans, A.J.M., Guex, N., Wiel, L., Nellaker, C., Amudhavalli, S.M., Banka, S., Bena, F.S., Ben-Zeev, B., Bonagura, V.R., Bruel, A.-L., Brunet, T., Brunner, H.G., Chew, H.B., Chrast, J., Cimbalistienė, L., Coon, H., Délot, E.C., Démurger, F., Denommé-Pichon, A.-S., Depienne, C., Donnai, D., Dyment, D.A., Elpeleg, O., Faivre, L., Gilissen, C., Granger, L., Haber, B., Hachiya, Y., Abedi, Y.H., Hanebeck, J., Hehir-Kwa, J.Y., Horist, B., Itai, T., Jackson, A., Jewell, R., Jones, K.L., Joss, S., Kashii, H., Kato, M., Kattentidt-Mouravieva, A.A., Kok, F., Kotzaeridou, U., Krishnamurthy, V., Kučinskas, V., Kuechler, A., Lavillaureix, A., Liu, P., Manwaring, L., Matsumoto, N., Mazel, B., McWalter, K., Meiner, V., Mikati, M.A., Miyatake, S., Mizuguchi, T., Moey, L.H., Mohammed, S., Mor-Shaked, H., Mountford, H., Newbury-Ecob, R., Odent, S., Orec, L., Osmond, M., Palculict, T.B., Parker, M., Petersen, A., Pfundt, R., Preikšaitienė, E., Radtke, K., Ranza, E., Rosenfeld, J.A., Santiago-Sim, T., Schwager, C., Sinnema, M., Blok, L.S., Spillmann, R.C., Stegmann, A.P.A., Thiffault, I., Tran, L., Vaknin-Dembinsky, A., Vedovato-dos-Santos, J.H., Vergano, S.A., Vilain, E., Vitobello, A., Wagner, M., Waheeb, A., Willing, M., Zuccarelli, B., Kini, U., Newbury, D.F., Kleefstra, T., Reymond, A., Fisher, S.E., and Vissers, L.E.L.M.

Abstract

Whereas large-scale statistical analyses can robustly identify disease-gene relationships, they do not accurately capture genotype-phenotype correlations or disease mechanisms. We use multiple lines of independent evidence to show that different variant types in a single gene, SATB1, cause clinically overlapping but distinct neurodevelopmental disorders. Clinical evaluation of 42 individuals carrying SATB1 variants identified overt genotype-phenotype relationships, associated with different pathophysiological mechanisms, established by functional assays. Missense variants in the CUT1 and CUT2 DNA-binding domains result in stronger chromatin binding, increased transcriptional repression and a severe phenotype. In contrast, variants predicted to result in haploinsufficiency are associated with a milder clinical presentation. A similarly mild phenotype is observed for individuals with premature protein truncating variants that escape nonsense-mediated decay, which are transcriptionally active but mislocalized in the cell. Our results suggest that in-depth mutation-specific genotype-phenotype studies are essential to capture full disease complexity and to explain phenotypic variability.

19. Light at the End of the “TUNEL”? Role of Ceramide in Seizure-induced Programmed Cell Death.

Author

Mikati, M.A, Abi-Habib, R.J., El Sabban, M.E., Dbaibo, G.S., Kurdi, R.M., Kobeissi, M., Farhar, F., Asaad, W., and Stafstrom, Carl E.

Subjects
*CELL death, *DEATH (Biology), *SPASMS, *EPILEPSY, *BRAIN diseases
Abstract

Hippocampal Programmed Cell Death after Status Epilepticus: Evidence for NMDA-receptor and Ceramide-mediated Mechanisms PURPOSE: Status epilepticus (SE) can result in acute neuronal injury with subsequent long-term age-dependent behavioral and histologic sequelae. To investigate potential mechanisms that may underlie SE-related neuronal injury, we studied the occurrence of programmed cell death (PCD) in the hippocampus in the kainic acid (KA) model. METHODS: In adult rats, KA-induced SE resulted in DNA fragmentation documented at 30 hours after KA injection. Ceramide, a known mediator of PCD in multiple neural and nonneural tissues, increased at 2 to 3 hours after KA intraperitoneal injection, and then decreased to control levels before increasing again from 12 to 30 hours after injection. MK-801 pretreatment prevented KA-induced increases in ceramide levels and DNA fragmentation, whether a reduction in seizure severity occurred or not (achieved with 5 mg/kg and 1 mg/kg of MK-801, respectively). RESULTS: Both ceramide increases and DNA fragmentation were observed after KA-induced SE in adult and in P35 rats. Ceramide did not increase after KA-induced SE in P7 pups, which also did not manifest any DNA fragmentation. Intrahippocampal injection of the active ceramide analogue C2-ceramide produced widespread DNA fragmentation, whereas the inactive ceramide analogue C2-dihydroceramide did not. CONCLUSIONS: Our data support the hypotheses that (a) N -methyl-d-aspartate–receptor activation results in ceramide increases and in DNA fragmentation; (b) ceramide is a mediator of PCD after SE; and (c) age-related differences occur in PCD and in the ceramide response after SE. Differences in the ceramide response could, potentially, be responsible for observed age-related differences in the response to SE. [ABSTRACT FROM AUTHOR]

Published
2003
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