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Nov 24, 2010 - Olimpia Musumeci • Maria Teresa Bassi •. Anna Mazzeo • Marina Grandis • Claudia Crimella •. Andrea Martinuzzi • Antonio Toscano. Received: ...

Neurol Sci (2011) 32:665–668 DOI 10.1007/s10072-010-0445-8

CASE REPORT

A novel mutation in KIF5A gene causing hereditary spastic paraplegia with axonal neuropathy Olimpia Musumeci • Maria Teresa Bassi • Anna Mazzeo • Marina Grandis • Claudia Crimella Andrea Martinuzzi • Antonio Toscano



Received: 18 February 2010 / Accepted: 19 October 2010 / Published online: 24 November 2010 Ó Springer-Verlag 2010

Abstract Hereditary spastic paraplegias (HSPs) include a group of neurodegenerative diseases, and so far 46 SPG loci have been mapped and 17 genes isolated. Among the autosomal dominant HSPs (AD-HSPs), SPG10 is a rare form due to mutations in KIF5A gene (locus 12q13.3). We describe the clinical, neurophysiological, morphological and genetic study of an Italian family with AD-HSP. The proband presented with an adult onset spastic paraparesis and diffuse paresthesias where neurophysiological and nerve biopsy morphological studies revealed an axonal neuropathy. Molecular genetic analysis identified a new missense mutation (c.608C[G) of KIF5A gene resulting in a serine to cysteine substitution, S203C, located in a highly conserved domain of the protein. This pedigree confirms the occurrence of an axonal peripheral neuropathy in SPG10.

O. Musumeci  A. Mazzeo  A. Toscano Department of Neurosciences, Psychiatry and Anaesthesiology, University of Messina, Messina, Italy M. T. Bassi  C. Crimella Laboratory of Molecular Biology IRCCS E. Medea, Bosisio Parini, Lecco, Italy M. Grandis Department of Neurosciences, Ophthalmology, and Genetics, University of Genova, Genova, Italy A. Martinuzzi IRCCS E. Medea Scientific Institute, Conegliano Research Centre, Conegliano, Italy O. Musumeci (&) UOC Neurologia e Malattie Neuromuscolari, AOU Policlinico G. Martino, via Consolare Valeria, 98125 Messina, Italy e-mail: [email protected]

Keywords Hereditary spastic paraplegia  KIF5A  SPG10  Peripheral neuropathy

Introduction Hereditary spastic paraplegias (HSPs) are genetically determined neurodegenerative disorders characterized by a wide clinical and genetic variability. Several neuropathological studies in these diseases have demonstrated the presence of a ‘‘dying back’’ process characterized by marked and symmetric reduction of axonal density in crossed and direct cortical spinal projections. Axonal loss is confined to the thoracic level of cortical spinal tract, while the somatosensory pathways are involved at the cervical level [1]. Clinically, HSPs are defined by progressive lower limb spasticity, hyperreflexia and weakness, and are frequently associated with urinary urgency and mild sensory disturbance. The presence of additional neurological and nonneurological signs and symptoms distinguishes complicated from pure forms [2]. However, even among typically ‘‘pure’’ forms there is an increasing recognition of extra cortico-spinal involvement such as lower motor neuron signs [3, 4], cognitive impairment [5, 6], ataxia [7], cerebral dysmorphisms [8] and neuropathy [9]. 70% of HSP reported cases are due to mutations in dominant loci; among them, mutations in few genes (SPG4-spastin, SPG3a-atlastin and possibly SPG31) are responsible for the majority of cases [10]. SPG10 is a rare form of autosomal dominant HSP (AD-HSP) caused by mutations in the neuronal kinesin heavy-chain KIF5A gene. Only few mutations of KIF5A have been described with either pure or complicated forms with a wide range of age of onset, from early childhood to

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the thirties. A recent study on a large cohort of AD-HSP Western European families reported that SPG10 accounts for about 10% of complicated forms suggesting that mutations in KIF5A represent the major cause of complicated form AD-HSP in France [11]. In SPG10, the most frequent associated feature was a sensory-motor neuropathy as previously reported [12]. Herein, we describe the clinical, neurophysiological, morphological and molecular genetic studies of a family from southern Italy with AD-HSP with associated sensorymotor neuropathy due to a novel mutation in KIF5A located in the kinesin motor domain.

Patients and methods The proband was a 49-year-old man who, since he was 35, complained of progressive walking difficulties, rigidity at lower limbs and distal paresthesias. Neurological examination revealed spastic gait, markedly increased muscle tone at lower limbs with mild pyramidal weakness, brisk proximal tendon reflexes with reduction of the distal ones at four limbs and a bilateral Babinsky sign. Additional features as bilateral distal wasting, pes cavus and decreased vibration sense distally in the legs were also present. There was no evidence of extrapyramidal signs, ataxia, cognitive impairment, deafness, retinal involvement, epilepsy or sphincteric disturbances. Blood tests including inflammatory indexes, folic acid and vitamin B12 and E levels were in the normal range. Brain and spinal cord MRI were normal. Neurophysiological studies revealed increased central conduction time of the motor evoked potential at lower limbs with normal responses in the upper extremities. The sensory evoked potentials were slightly abnormal, whereas brainstem and visual evoked potentials were within the normal range. Family history was positive for gait abnormalities suggesting an AD-HSP (Fig. 2): the father and one paternal uncle, both dead, suffered from similar symptoms, the oldest probands’ son (III-1, 28 years old) complained of rigidity at

lower limbs and gait disturbances since the age of 18. The other two siblings (III-2, III-3) were asymptomatic. Clinical and neurophysiological evaluations were performed in all the three sons of the proband: subject III-1 had a mild spastic gait with brisk reflexes at four limbs and a bilateral Babinski sign, while individuals III-2 and III-3 showed no neurological abnormalities. The proband underwent a sural nerve biopsy after informed consent. Blood samples were drawn from the proband and his unaffected sons after obtaining a written informed consent, and DNA was extracted with standard procedure. The affected son (III-1) refused molecular genetic analysis. The coding regions including the flanking intronic sequences of SPAST (SPG4 RefSeq NM_014946.3), ATL1 (RefSeq NM_015915.4 SPG3A) and KIF5A (SPG10, RefSeq NM_004984.2) genes were amplified using standard procedures. PCR products were directly sequenced with Big Dye Terminator Cycle Sequencing Kit (Applied Biosystem) and analyzed on an ABI 3130XL automated sequencer (Applied Biosystem). Two hundreds of ethnically matched controls were screened.

Results Electrophysiological study of the proband (II-3) revealed a chronic neurogenic pattern at four limbs. Nerve conduction velocity studies showed a sensory-motor axonal neuropathy more pronounced at lower limbs in II-3 and III-1 (Table 1), and were normal in III-2 and III-3 subjects. Sural nerve morphological examination revealed an axonal neuropathy without inflammatory infiltrates, signs of vasculitis or abnormal deposits in the endoneurial tissue (Fig. 1). Mutation analysis on the three genes, SPAST, SPG3A and KIF5A was conducted in the proband (II-3). A missense mutation in exon 8 of KIF5A gene (c.608C[G) was found, resulting in a serine to cysteine substitution S203C (Fig. 2), whereas it was absent in the two asymptomatic siblings (III-2, III-3). The substitution affects a highly conserved residue located in the switch domain I

Table 1 Electrophysiological findings in the affected members Peroneal nerve

Tibial nerve

Ulnar nerve

Sural nerve

NCV (m/s) cMAP (mV) DL (ms) NCV (m/s) cMAP (mV) DL (ms) NCV (m/s) cMAP (mV) DL (ms) NCV (m/s) SAP (lV) (45–60) (3–10) (3–4.8) (45–60) (3–10) (3–4.8) (55–70) (9–20) (2.3–3.7) (42–68) [10 II-3 36 III-1 42

0.4 0.4

8.6 7

37 39

0.6 0.4

7 7.8

57 52

18 5.8

The normal ranges are indicated in parenthesis NCV nerve conduction velocity, DL distal motor latency, CMAP compound muscle action potential

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5.8 4

– 37

Absent 3.5

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Fig. 1 Thin section of sural nerve biopsy: mild reduction of fiber density

c.608C>G-p.S203C

I

II

P 1

2

33*

III

C 1*

2*

3*

Switch 1 Mutant KIF5A H. sapiens M. musculus X. laevis D.melanogaster

VTNMNEHCSRSHSIFLINIKQENMET VTNMNEHSSRSHSIFLINIKQENMET VTNMNEHSSRSHSIFLINIKQENVET VTNMNEHSSRSHSIFLINIKQENIET VTNMNEHSSRSHSVFLINVKQENLEN

Fig. 2 Pedigree of the family analyzed is shown on the left; black and white symbols indicate affected and healthy subjects, respectively. Arrow indicates the proband, while the stars indicate subjects for whom DNA was available. On the right, the electropherograms encompassing the mutant and wild type sequence in the patient (P) and in control (C) are shown. At the bottom, the evolutionary conservation of the mutant residue within the switch I motif of the kinesin motor domain is shown

(consensus sequence NXXSSR, residues 199–204) of the kinesin motor domain.

Discussion We have identified a novel mutation in KIF5A gene in kindred with AD-HSP and have documented the associated clinical, electrophysiological and morphological findings

of peripheral nervous system involvement. In this family, the disease onset was in the second to the third decade with slow progression. The involvement of peripheral nerves consisted in a sensory-motor neuropathy more prevalent at lower limbs with mild clinical manifestations. No distal weakness were present in the two affected individuals. Sural nerve biopsy evidenced a moderated sensitive fibers loss in accordance with the clinical features. These findings confirm previous data of a recurrent peripheral nervous system involvement in SPG10 [13]. So far 15 KIF5A mutations have been reported and most of them are located in the highly conserved kinesin motor domain which plays an important role in the interaction with the neuronal microtubular system (Table 2) [11–17]. The mutation described in this study S203C disrupts the consensus sequence (NXXSSR, residue 199–204) of the switch I cluster within the motor domain of the protein close to the phosphate of the bound nucleotide that it is presumed to sense the presence (ATP) or absence (ADP) of a c-phosphate [18]. Several studies support the hypothesis that the kinesin superfamily is involved in various cellular functions by transporting different classes of organelles and vesicles in axons. In particular, KIF5A seems to be involved in the transport of neurofilaments along axons, and a defect in this transport is suggested to be the pathogenic mechanism in SPG10 [19]. Interestingly, another kinesin KIF1B is responsible of a subtype of Charcot-Marie-Tooth (type 2A1). Since KIF5A has a pan-neuronal expression with different distribution, as observed in mouse [20], we can hypothesize that the mutated protein may determine a degeneration of the cortico-spinal tracts as well as the peripheral nerves. Sural nerve biopsy in our index patient revealed a prevalent involvement of axons as primary neurodegenerative event. These data are in accordance with the electrophysiological studies showing in both affected individuals (II-3, III-1). A chronic denervation with increased duration of motor unit potentials with no sensory action on sural nerve and mild reduction of sensory and motor conduction velocities (Table 1) compatible with a sensorymotor axonal neuropathy more pronounced at lower limbs. Complex forms of AD-HSP with known causing genes are rare; SPG4, the more frequent form of AD-HSP, has been rarely associated with a complex phenotype and only two loci SPG9 and SPG29 and two genes (SAX1 and SPG17/BSCL2) account for a very small number of complex AD-HSP forms [4]. In particular, in these forms, the clinical phenotype is distinct with gastrointestinal or ocular problems in SPG9 and SPG29, and with a typical hands and feet amyotrophy in SPG17. The SPG3A form, although autosomal recessive is also frequent and often sporadic, presenting in pure or complicated forms, and should be considered in sporadic cases with mild sensory-motor

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Table 2 Spectrum of SPG10 mutations so far reported

Park parkinsonism, PNP peripheral neuropathy, MR mental retardation, RP retinitis pigmentosa, CMT CharcotMarie-Tooth disease

Exon

Mutation

Reference

9

c. 767 a[g

p. N256S

Pure HSP

Reid et al. [14]

c. 838 c[t

p. R280C

Pure HSP

Fichera et al. [15]

11

c. 1082 c[g

p. A361V

Pure HSP

Lo giudice et al. [13]

10

c. 1035 a[g

p. Y276C

Pure HSP

2

c.217 g[a

D73N

PNP

Blair et al. [16] Schu¨le et al. [12]

9

c. 759 g[t

p. K253N

PNP

9

c. 768_770 del CAA

p. N256del

PNP

Schu¨le et al. [12] Schu¨le et al. [12]

2

c. 188 a[g

p. Y63C

Park, deafness

Goizet et al. [11]

8

c. 593 t[c

p. M198T

PNP, park

Goizet et al. [11]

8

c. 611 g[a

p. R204Q

Silver syndrome-like

Goizet et al. [11]

9

c. 751 g[a

p. E251K

CMT-like

Goizet et al. [11]

9

c. 771 g[c

p. K257N

MR, PNP

Goizet et al. [11]

10

c. 839 g[t

p. R280L

Pure HSP

Goizet et al. [11]

10

c. 839 g[a

p. R280H

RP

Goizet et al. [11]

8 8

c. 610 c[t c. 608 g[c

p. R204W p. S203C

PNP PNP

Tessa et al. [17] Our study

Acknowledgments The study has been supported by governmental grants RF 2007-75, RC2008-2009, Ex Art56 PS Neuro, Cariplo foundation grant #2007.5156. The authors have reported no conflicts of

References 1. Fink JK (2006) Hereditary spastic paraplegia. Curr Neurol Neurosci Rep 6:65–76 2. McDermott C, White K, Bushby K, Shaw P (2000) Hereditary spastic paraparesis: a review of new developments. J Neurol Neurosurg Psychiatr 69:150–160 3. Dalpozzo F, Rossetto MG, Boaretto F et al (2004) Infancy onset hereditary spastic paraplegia associated with a novel atlastin mutation. Neurology 62:348 4. McDermott CJ, Burness CE, Kirby J et al (2006) Clinical features of hereditary spastic paraplegia due to spastin mutation. Neurology 67:45–51 5. Tallaksen CM, Guichart-Gomez E, Verpillat P et al (2003) Subtle cognitive impairment but no dementia in patients with spastin mutations. Arch Neurol 60:1113–1118 6. McMonagle P, Byrne P, Hutchinson M (2004) Further evidence of dementia in SPG4-linked autosomal dominant hereditary spastic paraplegia. Neurology 62:407–410

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Clinical features

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axonal neuropathy [9]. We suggest that in absence of a distal amyotrophy, detection of mild sensory-motor neuropathy in a patient with HSP can be a clue to look for SPG10 mutations. As reported in previous studies, we can conclude that a peripheral neuropathy is a recurrent feature in SPG10, and clinicians should be alerted to look for even minimal signs of peripheral nerves involvement to better address the genetic analysis.

Conflict of interest interest.

AA change

7. Nielsen JE, Johnsen B, Koefoed P et al (2004) Hereditary spastic paraplegia with cerebellar ataxia: a complex phenotype associated with a new SPG4 gene mutation. Eur J Neurol 11:817–824 8. Alber B, Pernauer M, Schwan A et al (2005) Spastin related hereditary spastic paraplegia with dysplastic corpus callosum. J Neurol Sci 236:9–12 9. Scarano V, Mancini P, Criscuolo C et al (2005) The R495W mutation in SPG3A causes spastic paraplegia associated with axonal neuropathy. J Neurol 252:901–903 10. Salinas S, Proukakis C, Crosby A, Warner TT (2008) Hereditary spastic paraplegia: clinical features and pathogenetic mechanisms. Lancet Neurol 7:1127–1138 11. Goizet C, Boukhris A, Mundwiller E et al (2009) Complicated forms of autosomal dominant hereditary spastic paraplegia are frequent in SPG10. Hum Mutat 30:E376–E385 12. Schu¨le R, Kremer BP, Kassubek J et al (2008) SPG10 is a rare cause of spastic paraplegia in European families. J Neurol Neurosurg Psychiatr 79:584–587 13. Lo Giudice M, Neri M, Falco M et al (2006) A missense mutation in the coiled-coil domain of the KIF5A gene and late-onset hereditary spastic paraplegia. Arch Neurol 63:284–287 14. Reid E, Kloos M, Ashley-Koch A, Hughes L, Bevan S et al (2002) A kinesin heavy chain (KIF5A) mutation in hereditary spastic paraplegia (SPG10). Am J Hum Genet 71:1189–1194 15. Fichera M, Lo Giudice M, Falco M, Sturnio M, Amata S et al (2004) Evidence of kinesin heavy chain (KIF5A) involvement in pure hereditary spastic paraplegia. Neurology 63:1108–1110 16. Blair MA, Ma S, Hedera P (2006) Mutation in KIF5A can also cause adult-onset hereditary spastic paraplegia. Neurogenetics 7:47–50 17. Tessa A, Silvestri G, de Leva MF, Modoni A, Denora PS et al (2008) A novel KIF5A/SPG10 mutation in spastic paraplegia associated with axonal neuropathy. J Neurol 255:1090–1092 18. Kikkawa M (2008) The role of microtubules in processive kinesin movement. Trends Cell Biol 18:128–135 19. Xia CH, Robets EA, Her LS, Liu X, Williams DS et al (2003) Abnormal neurofilament transport caused by target disruption of neuronal kinesin heavy chain KIF5A. J Cell Biol 161:55–66 20. Kanai Y, Okada Y, Tanaka Y, Harada A, Terada S, Hirokawa N (2000) KIF5C, a novel neuronal kinesin enriched in motor neurons. J Neurosci 20:6374–6384

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