6 doctors weighed in:
How is SMA diagnosed?
6 doctors weighed in

Holly Barth
General Practice
2 doctors agree
In brief: See below
(spinal muscular atrophy) defining signs and symptoms are the first clue.
To confirm diagnosis, a genetic test is done. If that is negative but the physician still things sma is the cause of the patient's symptoms, an electromyography, enzyme creatnine kinase, and nerve conduction studies can be done.

In brief: See below
(spinal muscular atrophy) defining signs and symptoms are the first clue.
To confirm diagnosis, a genetic test is done. If that is negative but the physician still things sma is the cause of the patient's symptoms, an electromyography, enzyme creatnine kinase, and nerve conduction studies can be done.
Holly Barth
Holly Barth
Answer assisted by Holly Barth, Medical Student
Thank
Dr. Richard Roberts
Clinical Genetics
1 doctor agrees
In brief: "Diagnosis based on
molecular genetic testing.
Mutations in SMN1...cause SMA; increases in SMN2 copy number often modify the phenotype. SMN1...is the primary gene in which mutation causes SMA. About 95%-98%...are homozygous for a deletion or gene conversion of SMN1 to SMN2 and about 2%-5% are compound heterozygotes for an SMN1 deletion or conversion mutation and an SMN1 intragenic mutation." coninued

In brief: "Diagnosis based on
molecular genetic testing.
Mutations in SMN1...cause SMA; increases in SMN2 copy number often modify the phenotype. SMN1...is the primary gene in which mutation causes SMA. About 95%-98%...are homozygous for a deletion or gene conversion of SMN1 to SMN2 and about 2%-5% are compound heterozygotes for an SMN1 deletion or conversion mutation and an SMN1 intragenic mutation." coninued
Dr. Richard Roberts
Dr. Richard Roberts
Thank
2 comments
Dr. Richard Roberts
"SMN1 deletion or conversion mutation is typically detected by demonstrating the absence of exon 7, since it can be easily differentiated from exon 7 of SMN2. Note that the SMN1 to SMN2 conversion mutations cannot be differentiated from SMN1 deletions by standard deletion testing, as both result in the absence of SMN1 exon 7." http://www.ncbi.nlm.nih.gov/books/NBK1352/
Dr. Richard Roberts
Tbe ACMGG issued this policy statement in 3/2015: https://www.acmg.net/docs/ACMG_Clinical%20Utility%20of%20Genetic%20and%20Genomic%20Services%20GIM%20JUne%202015.pdf
Dr. Alan Patterson
Obstetrics & Gynecology
1 doctor agrees
In brief: Blood test will show
If u are a carrier, if u are then husband needs to be checked < I do sma testing on all my pregnant patients.

In brief: Blood test will show
If u are a carrier, if u are then husband needs to be checked < I do sma testing on all my pregnant patients.
Dr. Alan Patterson
Dr. Alan Patterson
Thank
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