Alpers syndrome (Alpers-Huttenlocher syndrome)

Mitochondrial disorders are clinically heterogeneous and result from dysfunction of the mitochondrial respiratory chain, which can be caused by mutations in mitochondrial DNA (mtDNA) or in nuclear genes. Mitochondrial disorders may affect a single organ, but many involve multiple organ systems particularly those that are highly dependent on aerobic metabolism (brain, skeletal muscle, heart, kidney and endocrine system). Patients may present at any age; however, nuclear DNA mutations generally present in childhood and mtDNA mutations generally present in late childhood or in adults. Some affected individuals exhibit clinical features that fall into a discrete clinical syndrome, such as Leber’s Hereditary Optic Neuropathy (LHON), Kearns-Sayre syndrome (KSS), chronic progressive external ophthalmoplegia (CPEO), mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS), myoclonic epilepsy with ragged-red fibers (MERRF), neurogenic weakness with ataxia and retinitis pigmentosa (NARP) or Leigh syndrome (LS). However, often the clinical features are highly variable and non-specific and many affected persons do not fit into one particular category. Similar clinical features can be caused by mtDNA mutations or nuclear gene mutations. Common features of mitochondrial disease may include ptosis, external ophthalmoplegia, proximal myopathy, exercise intolerance, cardiomyopathy, sensorineural deafness, optic atrophy, pigmentary retinopathy, diabetes mellitus, encephalopathy, seizures, dementia, migraine, stroke-like episodes, ataxia, spasticity, chorea and dementia. Recently, it has been estimated that approximately 7% of patients diagnosed with autism may have an underlying disorder of mitochondrial function .The prevalence of mitochondrial disorders has been estimated 1/5000 to 1/8500 Abnormal amounts of mtDNA, either depletion or amplification (over-replication), can be indicative of mitochondrial dysfunction. Mitochondrial DNA depletion syndrome is a group of mitochondrial disorders characterized by a reduced amount of mitochondrial DNA in tissues. The disorders associated with mtDNA depletion syndrome generally involve neurological symptoms that can occur during infancy or childhood. Symptoms may include muscle weakness, hypotonia, exercise intolerance, developmental delay, lactic acidosis, encephalopathy, hepatopathy, or myopathy. Mitochondrial over-replication can be a cellular response to mitochondrial dysfunction and is characterized by ragged red fibers in the affected muscle specimens of patients with mtDNA mutations in tRNA genes or with large scale mtDNA deletions. Over-replication of mtDNA has also been reported in a later-onset, mild Kearns Sayre syndrome patient with a high heteroplasmy (92%) for a deletion in the mtDNA POLG gene mutations are one of the most common causes of inherited mitochondrial disease. Mutations in the POLG gene cause a spectrum of mitochondrial diseases (see above), with onset ages from the neonatal period to late adult life, including PEO, SANDO, Alpers syndrome, and MNGIE. The clinical presentation ranges from severe encephalopathy and liver failure to late onset external ophthalmoplegia, seizures, ataxia, myopathy and isolated muscle pain. Other findings include cardiomyopathy, cardiac conduction defects, depression, hearing loss, diffuse degeneration of cerebral gray matter, hepatic cirrhosis, and diffuse leukoencephalopathy. Parkinsonism and premature ovarian failure have also been described.Because of the overlap in phenotypes and differences in age of onset, definitive diagnosis of these disorders is dependent upon mutation identification

Tests Available

Forms and Documents

Test Details

ADSL, CACNA1A, CDKL5, CHD2, CHRNA2, CHRNA4, CHRNA7, CHRNB2, CLN3, CLN5, CLN6, CLN8, CNTNAP2, CSTB, CTSD, DYRK1A, EEF1A2, EPM2A, FOLR1, FOXG1, GABRA1, GABRB2, GABRB3, GABRG2, GAMT, GATM, GOSR2, GRIN1, GRIN2A, IQSEC2, KANSL1, KCNT1, KCTD7, LGI1, MAGI2, MBD5, MECP2, MEF2C, MFSD8, NHLRC1, NRXN1, PCDH19, PNKP, POLG, PPT1, PRICKLE1, SCN1A, SCN1B, SCN2A, SLC2A1, SLC6A8, SLC9A6, TBC1D24, TCF4, TPP1 (CLN2), UBE3A, WDR45, ZEB2
  • Molecular confirmation of a clinical diagnosis
  • To assist with decisions about treatment and management of individuals with epilepsy
  • Testing of at-risk relatives for specific known mutation(s) previously identified in an affected family member
  • Prenatal diagnosis for known familial mutation(s) in at-risk pregnancies
  • Exon Array CGH
  • Next-Gen Sequencing

Ordering

542
4 weeks
2-5 mL Blood - Lavender Top Tube
Oral Rinse (30-40 mL)|Buccal Swabs

Billing

81404x2, 81405x2, 81406x2, 81407x1
Yes
Yes
* For price inquiries please email zebras@genedx.com

References

  1. Berg et al. (2010) Epilepsia 51: 676-685
  2. Pellock, JM (2004) Neurol (2004) 62:S17-S23.
  3. Pong et al., (2011) Pediatr Neurol 44:317-327.
  4. Weber et al., (2008) Dev Med Child Neurol 50:648-654.
  5. Nicita et al., (2011) Seizure: Eur J Epilepsy doi:10.1016/j.seizure.2011.08.007
  6. Ottman et al., (2010) Epilepsia 51:655-670.
  7. Pal et al., (2010) Nat Rev Neurol 6:445-453.
  8. Macdonald et al., (2010) J Physiol 588:1861-1869.
  9. Andrade DM (2009) Hum Genet 126:173-193
  10. Ramachandran et al., (2009) Epilepsia 50:29-36
  11. Steinlein et al., (2004) Nat Rev Neurosci 5:401-408.
  12. Bennett S. (2004) Pharmacogenomics 5:433-8.
  13. Falace et al., (2010) Am J Hum Genet 87:365-370.

Forms and Documents

Test Details

ADSL, ALDH7A1, ALG13, ARHGEF9, ARX, ATP1A2, ATP6AP2, CACNA1A, CDKL5, CHD2, CHRNA2, CHRNA4, CHRNA7, CHRNB2, CLN3, CLN5, CLN6, CLN8, CNTNAP2, CSTB, CTSD, DNAJC5, DNM1, DYRK1A, EEF1A2, EPM2A, FOLR1, FOXG1, GABRA1, GABRB2, GABRB3, GABRG2, GAMT, GATM, GOSR2, GRIN1, GRIN2A, GRIN2B, IQSEC2, KANSL1, KCNB1, KCNJ10, KCNQ2, KCNQ3, KCNT1, KCTD7, LGI1, MAGI2, MBD5, MECP2, MEF2C, MFSD8, NHLRC1, NR2F1, NRXN1, PCDH19, PIGA, PIGO, PIGV, PNKP, PNPO, POLG, PPT1, PRICKLE1, PRRT2, QARS, SCARB2, SCN1A, SCN1B, SCN2A, SCN8A, SLC13A5, SLC25A22, SLC2A1, SLC6A8, SLC9A6, SPTAN1, STXBP1, TBC1D24, TCF4, TPP1 (CLN2), TSC1, TSC2, UBE3A, WDR45, WWOX, ZEB2
  • Molecular confirmation of a clinical diagnosis
  • To assist with decisions about treatment and management of individuals with epilepsy
  • Testing of at-risk relatives for specific known mutation(s) previously identified in an affected family member
  • Prenatal diagnosis for known familial mutation(s) in at-risk pregnancies
  • Exon Array CGH
  • Next-Gen Sequencing

Ordering

523
4 weeks
2-5 mL Blood - Lavender Top Tube
Oral Rinse (30-40 mL)|Buccal Swabs

Billing

81405x2, 81406x4, 81407x2
Yes
Yes
* For price inquiries please email zebras@genedx.com

References

  1. Bennett S. Pharmacogenomics (2004) 5:433-8.
  2. Andrade DM. Genetic basis in epilepsies caused by malformations of cortical development and in those with structurally normal brains. Hum Genet (2009) 126:173-193.
  3. Macdonald et al. Mutations in GABA receptor subunits associated with genetic epilepsies. J Physiol (2010) 588:1861-1869.
  4. Ottman et al. Genetic testing in the epilepsies – Report of the ILAE Genetics Commission. Epilepsia (2010) 51:655-670.
  5. Weber et al., Genetic mechanisms in idiopathic epilepsy Dev Med Child Neurol (2008) 50:648-654.
  6. Nicita et al., The genetics of monogenic idiopathic epilepsies and epileptic encephalopathy Seizure: Eur J Epilepsy (2011) doi:10.1016/j.seizure.2011.08.007
  7. Deprez et al. Genetics of epilepsy syndromes starting in the first year of life. Neurology (2009) 72:273-281.
  8. Berg et al. Revised terminology and concepts for organization of seizures and epilepsies: Report of the ILAE Commision on Classification and Terminology, 2005- 2009. Epilepsia (2010) 51: 676-685.
  9. Ramachandran et al. The autosomal recessively inherited progressive myoclonus epilepsies and their genes Epilepsia (2009) 50:29-36.
  10. Steinlein et al. Genetic mechanisms that underlie epilepsy. Nat Rev Neurosci (2004) 5:401-408.
  11. Pal et al. Genetic evaluation and counseling for epilepsy. Nat Rev Neurol (2010) 6:445-453
  12. Pellock, JM. Understanding co-morbidities affecting children with epilepsy. Neurol (2004) 62:S17-S23.
  13. Pong et al. Developments in molecular genetic diagnostics: An update for the pediatric epilepsy specialist Pediatr Neurol (2011) 44:317-327

Forms and Documents

Test Details

POLG
  • Confirmation of biochemical and clinical diagnosis
  • Carrier testing
  • Prenatal diagnosis when familial mutations are known
  • Capillary Sequencing

Ordering

394
4-5 weeks
2-5 mL Blood - Lavender Top Tube
Oral Rinse (30-40 mL)|Buccal Swabs

Billing

81406x1
No
Yes
* For price inquiries please email zebras@genedx.com

References

  1. McFarland et al., (2008) Arch Dis Child 93:151-153
  2. Horvath et al., (2006) Brain 129:1674-1684
  3. Wong et al., (2008) Hum Mutat 29:E150-E172
  4. Blok et al., (2009, Jul 2) J Med Genet [Epub ahead of print]
  5. Agostino et al., (2003) Neurology 60:1354-1356

Forms and Documents

Test Details

ALDH7A1, ARX, CDKL5, FOLR1, KCNQ2, KCNQ3, KCNT1, MECP2, MEF2C, PCDH19, PNPO, POLG, SCN1A, SCN1B, SCN2A, SCN8A, SLC2A1, SLC6A8, SPTAN1, STXBP1, TSC1, TSC2
  • Molecular confirmation of a clinical diagnosis
  • To assist with decisions about treatment and management of individuals with epilepsy
  • Testing of at-risk relatives for specific known mutation(s) previously identified in an affected family member
  • Prenatal diagnosis for known familial mutation(s) in at-risk pregnancies
  • Exon Array CGH
  • Next-Gen Sequencing

Ordering

814
2 weeks
2-5 mL Blood - Lavender Top Tube
Oral Rinse (30-40 mL)|Buccal Swabs

Billing

81405x2, 81406x3, 81407x1
Yes
Yes
* For price inquiries please email zebras@genedx.com

References

  1. Ottman et al., (2010) Epilepsia 51:655-670.
  2. Pong et al., (2011) Pediatr Neurol 44:317-327.
  3. Nicita et al., (2011) Seizure: Eur J Epilepsy doi:10.1016/j.seizure.2011.08.007
  4. Zucca et al., (2008) Arch Neurol 65:489-494.
  5. Harkin et al., (2007) Brain 130:843-852.
  6. Higurashi et al., (2011) Epilepsy Res dio:10.1016/j.eplepsyres.2011.10.014.
  7. Depienne et al., (2009) Plos Genet 5(2):e1000381.
  8. Marini et al., (2010) Neurology 75:646-653.
  9. Hynes et al., (2010) J Med Genet 47:211-216.
  10. Depienne et al., (2010) Hum Mutat 32:E1959-E1975.
  11. Weckhuysen et al., (2012) Ann Neurol 71:15-25.
  12. Carvill et al., (2014) Neurol 82:1245-1253.
  13. Mills et al., (2010) Brain 133:2148-2159.
  14. Nguyen et al., (2006) J Hepatol 45:108-116.
  15. Isohanni et al., (2011) Neurol 76:811-815.
  16. Hunter et al., (2011) Pediatr Neurol 45:311-318.
  17. Kamiya et al., (2004) J Neurosci 24(11):2690-2698.
  18. Ogiwara et al., (2009) Clin Genet 73(13):1046-1053.
  19. Veeramah et al., (2012) Am J Hum Genet 90:502-510.
  20. Saitsu et al., (2010) Am J Hum Genet 886:881-891.
  21. Gospe et al., (2010) Chang Gung Med 33:1-12.
  22. Li et al., (2006) J Hum Genet 52:38-47.
  23. Tao et al., (2004) Am J Hum Genet 75:1149-1154.
  24. Rosas-Vargas et al., (2008) J Med Genet 45:172-178.
  25. Zweier et al., (2010) Hum Mutat 31:722-733.
  26. Grapp et al., (2012) Brain 135:2022-2031.
  27. EpiPM Consortium (2015) Lancet Neurol 14:1219–28.
  28. Wirrell et al., (2015) Epilepsia 56(4):617–625 3

Forms and Documents

Test Details

  • Molecular confirmation of a clinical diagnosis
  • To assist with decisions about treatment and management of individuals with epilepsy
  • Testing of at-risk relatives for specific known variant(s) previously identified in an affected family member
  • Prenatal diagnosis for known familial pathogenic variant(s) in at-risk pregnancies
  • Next-Gen Sequencing

Ordering

921
6 weeks
2-5 mL Blood - Lavender Top Tube
Oral Rinse (30-40 mL)|Buccal Swabs

Billing

81404x4, 81405x3, 81406x2, 81407x1, 81408x2
Yes
Yes
* For price inquiries please email zebras@genedx.com

References

  1. Pong et al. (2011) Pediatric Neurology 44 (5):317-27 (PMID: 21481738)
  2. Dyment et al. (2014) Clinical Genetics : (PMID: 25046240)
  3. Michaud et al. (2014) Human Molecular Genetics 23 (18):4846-58 (PMID: 24781210)
  4. Veeramah et al. (2013) Epilepsia 54 (7):1270-81 (PMID: 23647072)
  5. Allen et al. (2013) Nature 501 (7466):217-21 (PMID: 23934111)
  6. EuroEPINOMICS-RES et al. American Journal Of Human Genetics 95 (4):360-370 (PMID: 25262651)
  7. Lee et al. (2014) Jama 312 (18):1880-7 (PMID: 25326637)
  8. McKnight D, Retterer K, Juusola J, Brandt T, Richard G, and Suchy S, Genetic Testing Strategies for Patients with Epilepsy and Neurodevelopmental Disorders; (Abstract #562). Presented at the 2015 ACMG Annual Clinical Genetics Meeting, March 27, 2015, Salt

Forms and Documents

Test Details

ADSL, ALDH7A1, ALG13, ARHGEF9, ARID1B, ARX, ATP1A2, ATP6AP2, ATRX, CACNA1A, CASK, CDKL5, CHD2, CHRNA2, CHRNA4, CHRNA7, CHRNB2, CLN3, CLN5, CLN6, CLN8, CNTNAP2, CREBBP, CSTB, CTSD, DNAJC5, DYRK1A, EEF1A2, EHMT1, EPM2A, FOLR1, GABRA1, GABRB2, GABRB3, GABRG2, GAMT, GATM, GOSR2, GRIN1, GRIN2A, GRIN2B, HNRNPU, IQSEC2, KANSL1, KCNB1, KCNJ10, KCNQ2, KCNQ3, KCNT1, KCTD7, LGI1, MAGI2, MBD5, MECP2, MEF2C, MFSD8, NHLRC1, NR2F1, NRXN1, OPHN1, PCDH19, PHF6, PIGA, PIGO, PIGV, PLCB1, PNKP, PNPO, POLG, PPT1, PRICKLE1, PRRT2, QARS, SCARB2, SCN1A, SCN1B, SCN2A, SCN8A, SLC13A5, SLC25A22, SLC2A1, SLC9A6, SMC1A, SPTAN1, STXBP1, SYNGAP1, TBC1D24, TCF4, TPP1 (CLN2), TSC1, TSC2, UBE3A, WDR45, WWOX, ZEB2
  • Molecular confirmation of a clinical diagnosis
  • To assist with decisions about treatment and management of individuals with epilepsy
  • Testing of at-risk relatives for specific known variant(s) previously identified in an affected family member
  • Prenatal diagnosis for known familial pathogenic variant(s) in at-risk pregnancies
  • Exon Array CGH

Ordering

953
4 weeks
2-5 mL Blood - Lavender Top Tube
Oral Rinse (30-40 mL)|Buccal Swabs

Billing

81304x1, 81403x1, 81405x3, 81406x2
No
Yes
* For price inquiries please email zebras@genedx.com