A Simple Guide to Spinal Muscular Atrophy, Diagnosis, Treatment and Related Conditions

By Kenneth Kee

This book describes Spinal muscular atrophy, Diagnosis and Treatment and Related Diseases

Recently a 5 month old Singapore boy diagnosed with Spinal muscular atrophy Type 1 will be able to obtain the $3 million Zolgensma single dose medicine treatment. This medicine is the most expensive medicine in the world. This is to be followed by a regime of Risdiplam costing $15,000 for 64 days and possible steroids to prevent liver damage.

Spinal muscular atrophy is a genetic disorder featured by weakness and wasting (atrophy) in muscles utilized for movement (skeletal muscles).

It is produced by a loss of specialized nerve cells termed motor neurons that regulate muscle movement.

The weakness is likely to be more severe in the muscles close to the center of the body (proximal) compared to muscles away from the body's center (distal).

The muscle weakness normally becomes worse with age.

There are many types of spinal muscular atrophy produced by alterations in the same genes.

The types differ in age of start and severity of muscle weakness with overlap between the types.
SMA type 0 (Congenital disease) - evident before birth and is the rarest of the SMA
SMA type I (Werdnig-Hoffmann disease) - affects babies less than six months old.
SMA type II (Dubowitz disease) - develops in babies between 7 and 18 months old.
SMA type III (Kugelberg-Welander disease) - appears after 18 months of age.
SMA type IV (Adult disease) - this type of SMA patients is diagnosed in adulthood.

Other types of SMA and linked motor neuron diseases are caused by mutations in other genes such as:
Spinal muscular atrophy that has progressive myoclonic epilepsy,
Spinal muscular atrophy that has lower extremity predominance,
X-linked infantile spinal muscular atrophy, and
Spinal muscular atrophy that has respiratory distress type 1.
Congenital spinal muscular atrophy with arthrogryposis (persistent contracture of joints with fixed abnormal posture of the limb)
Kennedy’s disease, termed progressive spinobulbar muscular atrophy, may first be identified between 15 and 60 years of age.
Distal spinal muscular atrophy (DSMA) a type of spinal muscular atrophy that mostly involves the hands, feet, lower arms, and lower legs.

The symptoms of spinal muscular atrophy happen depending on the type of SMA present in the affected person, and the age the person acquires the genetic disorder:
Weakness in muscles with sudden jolting movements
Difficulty in breathing and swallowing of food
Irregular shape of limbs, chest, spine due to a decrease in muscle strength
Problems with sitting, standing and walking normally
Higher risk of acquiring respiratory disorders and infections

Diagnoses could be made by prenatal screening or by gene panel investigation and muscle biopsy.

Polymerase chain reaction (PCR) or multiplex ligation probe amplification (MLPA) can help to determine the homozygous exon 7 deletion in the SMN1 gene.

The treatment has mainly been supportive in the past
Physiotherapy-non-invasive ventilation, Airway clearance
Gene Therapy
Stem Cell Therapy

New treatments have been produced that are combating the very poor morbidity and mortality linked with SMA I and II.

Zolgensma is a single dose intravenous injection gene therapy that allow the body to produce functioning SMN protein.
All patients were alive at 20 months compared to expected 8% in other therapies
Risdiplam is an oral medicine that acts via modifying SMN2 splicing.
Nusinersen is an intra-thecally delivered antisense oligonucleotide (ASO) that provides functional SMN2 formation

TABLE OF CONTENT
Introduction
Chapter 1 Spinal muscular atrophy
Chapter 2 Causes
Chapter 3 Symptoms
Chapter 4 Diagnosis
Chapter 5 Treatment
Chapter 6 Prognosis
Chapter 7 Muscle Atrophy
Chapter 8 Floppy Baby
Epilogue

• Language: English
• Publisher: Kenneth Kee
• Release date: Nov 13, 2022
• ISBN: 9781005729028

Kenneth Kee

Medical doctor since 1972.Started Kee Clinic in 1974 at 15 Holland Dr #03-102, relocated to 36 Holland Dr #01-10 in 2009.Did my M.Sc (Health Management ) in 1991 and Ph.D (Healthcare Administration) in 1993.Dr Kenneth Kee is still working as a family doctor at the age of 74However he has reduced his consultation hours to 3 hours in the morning and 2 hours inthe afternoon.He first started writing free blogs on medical disorders seen in the clinic in 2007 on http://kennethkee.blogspot.com.His purpose in writing these simple guides was for the health education of his patients which is also his dissertation for his Ph.D (Healthcare Administration). He then wrote an autobiography account of his journey as a medical student to family doctor on his other blog http://afamilydoctorstale.blogspot.comThis autobiography account “A Family Doctor’s Tale” was combined with his early “A Simple Guide to Medical Disorders” into a new Wordpress Blog “A Family Doctor’s Tale” on http://ken-med.com.From which many free articles from the blog was taken and put together into 1000 eBooks.He apologized for typos and spelling mistakes in his earlier books.He will endeavor to improve the writing in futures.Some people have complained that the simple guides are too simple.For their information they are made simple in order to educate the patients.The later books go into more details of medical disorders.He has published 1000 eBooks on various subjects on health, 1 autobiography of his medical journey, another on the autobiography of a Cancer survivor, 2 children stories and one how to study for his nephew and grand-daughter.The purpose of these simple guides is to educate patient on health disorders and not meant as textbooks.He does not do any night duty since 2000 ever since Dr Tan had his second stroke.His clinic is now relocated to the Buona Vista Community Centre.The 2 units of his original clinic are being demolished to make way for a new Shopping Mall.He is now doing some blogging and internet surfing (bulletin boards since the 1980's) startingwith the Apple computer and going to PC.The entire PC is upgraded by himself from XT to the present Pentium duo core.The present Intel i7 CPU is out of reach at the moment because the CPU is still expensive.He is also into DIY changing his own toilet cistern and other electric appliance.His hunger for knowledge has not abated and he is a lifelong learner.The children have all grown up and there are 2 grandchildren who are even more technically advanced than the grandfather where mobile phones are concerned.This book is taken from some of the many articles in his blog (now with 740 posts) A Family Doctor’s Tale.Dr Kee is the author of:"A Family Doctor's Tale""Life Lessons Learned From The Study And Practice Of Medicine""Case Notes From A Family Doctor"

Book preview

A

Simple

Guide

To

Spinal Muscular Atrophy,

Diagnosis,

Treatment

And

Related Conditions

By

Dr Kenneth Kee

M.B.,B.S. (Singapore)

Ph.D (Healthcare Administration)

Copyright Kenneth Kee 2022 Smashwords Edition

Published by Kenneth Kee at Smashwords.com

Dedication

This book is dedicated

To my wife Dorothy

And my children

Carolyn, Grace

And Kelvin

This book describes Spinal muscular atrophy, Diagnosis and Treatment and Related Diseases which is seen in some of my patients in my Family Clinic.

(What You Need to Treat Spinal muscular atrophy)

This e-Book is licensed for your personal enjoyment only. This eBook may not be re-sold or given away to other people. If you would like to share this book with another person, please purchase an additional copy for each reader.

If you’re reading this book and did not purchase it, or it was not purchased for your use only, then please return to Smashwords.com and purchase your own copy.

Thank you for respecting the hard work of this author.

Introduction

I have been writing medical articles for my blog: http://kennethkee.blogspot.com (A Simple Guide to Medical Disorder) for the benefit of my patients since 2007.

My purpose in writing these simple guides was for the health education of my patients.

Health Education was also my dissertation for my Ph.D (Healthcare Administration).

I then wrote an autobiography account of my journey as a medical student to family doctor on my other blog: http://afamilydoctorstale.blogspot.com.

This autobiography account A Family Doctor’s Tale was combined with my early A Simple Guide to Medical Disorders into a new Wordpress Blog A Family Doctor’s Tale on http://kenkee481.wordpress.com.

From which many free articles from the blog was taken and put together into 800 eBooks.

Some people have complained that the simple guides are too simple.

For their information they are made simple in order to educate the patients.

The later books go into more details of medical disorders.

The first chapter is always from my earlier blogs which unfortunately tends to have typos and spelling mistakes.

Since 2013, I have tried to improve my spelling and writing.

As I tried to bring the patient the latest information about a disorder or illness by reading the latest journals both online and offline, I find that I am learning more and improving on my own medical knowledge in diagnosis and treatment for my patients.

My diagnosis and treatment capability has improved tremendously from my continued education.

Just by writing all these simple guides I find that I have learned a lot from your reviews (good or bad), criticism and advice.

I am sorry for the repetitions in these simple guides as the second chapters onwards have new information as compared to my first chapter taken from my blog.

I also find repetition definitely help me and maybe some readers to remember the facts in the books more easily.

I apologize if these repetitions are irritating to some readers.

Chapter 1

Spinal muscular atrophy

Recently a 5 month old Singapore boy diagnosed with Spinal muscular atrophy Type 1 will be able to obtain the $3 million Zolgensma single dose medicine treatment. This is to be followed by a regime of Risdiplam costing $15,000 for 64 days and possible steroids to prevent liver damage.

What is Spinal muscular atrophy?

Spinal muscular atrophy is a genetic disorder featured by weakness and wasting (atrophy) in muscles utilized for movement (skeletal muscles).

It is produced by a loss of specialized nerve cells termed motor neurons that regulate muscle movement.

The weakness is likely to be more severe in the muscles close to the center of the body (proximal) compared to muscles away from the body's center (distal).

The muscle weakness normally becomes worse with age.

There are many types of spinal muscular atrophy produced by alterations in the same genes.

The types differ in age of start and severity of muscle weakness with overlap between the types.

Types of SMA

1. SMA type 0 (Congenital disease) - evident before birth and is the rarest of the SMA

2. SMA type I (Werdnig-Hoffmann disease) - affects babies less than six months old.

3. SMA type II (Dubowitz disease) - develops in babies between 7 and 18 months old.

4. SMA type III (Kugelberg-Welander disease) - appears after 18 months of age.

5. SMA type IV (Adult disease) - this type of SMA patients is diagnosed in adulthood.

Other types of spinal muscular atrophy and linked motor neuron diseases are produced by mutations in other genes such as:

1. Spinal muscular atrophy that has progressive myoclonic epilepsy,

2. Spinal muscular atrophy that has lower extremity predominance,

3. X-linked infantile spinal muscular atrophy, and

4. Spinal muscular atrophy that has respiratory distress type 1.

Spinal muscular atrophy (SMA) is heterogeneous in presentation and differs from death within weeks of birth to mild proximal weakness forming during adulthood.

Earlier manifestations are normally linked with poorer function and prognosis: classification of SMA subtypes is categorized by the age of onset and medical severity and life expectancy.

Spinal Muscular Atrophy (SMA) is a genetic disorder under the scope of the neurodegenerative disorders and Motor Neuron Disease MND.

It is featured by degeneration of alpha motor neurons in the spinal cord that involves the regulation of voluntary muscle movement.

Incidence

Spinal muscular atrophy involves 1 per 8,000 to 10,000 people worldwide.

Spinal muscular atrophy Type I is the most frequent type, responsible for about 50% of all cases.

SMA Types II and III are the next most frequent while Types 0 and IV are rare.

SMA incidence has been evaluated at 1 in 6000 to 11000, with a carrier incidence in the mutations in SMN1 of 2 to 3% (1 in 40) in the general population.

Incidence ranges depending to ethnicity, with the incidence of 8/100,000 for people of white when compared with 0.89 in 100,000 for black and 0.96/100,000 for those of mixed ethnicity.

While people should anticipate a higher incidence of live births with SMA, one belief is that fetuses possessing 0 copies of SMN1+SMN2 fail to form unlike other species with this genotype

The disease is featured as an autosomal recessive disorder with an incidence of about 1 in 6-10,000 births affected by SMA with a carrier incidence of 1 in 35-70.

Pathophysiology

The exact part SMN protein plays in neuronal function and development is not fully known and its later absence causing such destructive deficits has not been understood.

SMN protein is present in all eukaryotic cells and has demonstrated to play an important part in all cells concerning homeostatic cellular pathways.

There are two main hypotheses that relate to SMN protein’s part in

1. The neuronal cytoplasm and

SMN protein in the cytoplasm has shown a very important part in mRNA transport through axons, actins dynamics, and vesicle secretion in the synapse.

2. The neuronal nucleus.

In the nucleus, SMN protein develops small nuclear RNA’s (snRNA) and hence plays a key part in the formation of the spliceosome, which removes introns in pre-mRNA into functional mRNA.

The spliceosome is gathered from small nuclear RNAs and many proteins.

This theory elucidates the injury to motor neurons, mainly to either neuronal sensitivity to malfunction directly or indirectly through incorrectly spliced mRNA producing dysfunctional proteins important to neuronal function.

Recent advances in the comprehension of SMN protein concerning its omnipresent presence and multiple functions in all eukaryotic cells have revealed that SMA is not just a motor neuron disorder with congenital heart disorder links and sensory nerve pathology in SMA type 1.

What is