Snyder-Robinson Syndrome Medical Management by Mary Jo Kutler

The purpose of this presentation is to discuss the many different medical issues seen in different patients with Snyder-Robinson Syndrome, even the ones that have not been published in literature. There are medical issues mentioned in the presentation are not necessarily statistically significant, but rather based on the information from the Natural History Study and journal articles written about SRS patients.

This presentation is for clinicians, researchers, and SRS families.

To the families: it’s important to understand that there is a wide range of medical issues and the goal is to bring awareness to symptoms that have been experienced by some, but not ALL, SRS patients.

To researchers, scientists, and other clinicians: This information is to help you understand what other mechanisms you may want to consider when working with your patients & give you a platform to work with while considering future treatment options.

Seizures

Seizure activity varies greatly for individuals with SRS. There are some without any seizures while others may see more frequent and severe seizures.

Seizure type may include:

Infantile spasms

Lennox Gastaut

Tonic and myoclonic (most common)

Atonic

Tonic-clonic

Atypical absence

Complex partial

Focalized

The most important thing for families is noticing/treating the seizures (not as much figuring out the exact type). It’s good to be on the look out because seizures are typically brief – they can last a few seconds to one minute, and therefore can easily go unnoticed.

Don’t be discouraged if you need to try many different anti-seizure medications before finding one that works.

Vision (Ophthalmology)

Cortical Vision Impairment (CVI): visual impairment (issues with sight) caused by brain dysfunction CVI may present in the following ways:

Not able to follow, focus, or track with eyes

Sensitivity to light (called photophobia)

Inconsistent visual responses with an avoidant gaze

Nearsightedness (Myopia)

Other issues that have been reported in SRS patients:

crowded drusen

pale optic nerve

torpedo shaped retinal lesion

pigmented retina

eye pain

photophobia

Hearing

Hearing impairment

Some SRS patients have sensorineural and/or conductive hearing impairment that require hearing aids.

A few SRS males have hearing loss, which have been reported as progressive (or getting worse over time).

Recommendation: Yearly hearing exams should be performed. It would be good to have the hearing specialist (audiologist) compare the waveforms to previous exams to see if there are any changes or if hearing is getting worse over time.

Lungs (Pulmonology)

Reactive Airway Disease: SRS patients may have a history of asthma, but also might show other breathing (respiratory) issues that don’t have a clear cause

Some SRS patients have an abundance of respiratory/mucous secretions, which are extra-thick.

Treatments for lung-related issues vary and include:

oral steroids

bronchodilators

hypertonic saline

acetylcysteine

inhaled corticosteroids

Serious breathing issues/apnea may require CPAP/BiPAP

Tracheostomies in some severe cases

For help clearing the airways, some SRS patients have used these treatments:

Suctioning

chest physiotherapy

cough assist and/or supplemental oxygen

Recommendation: For breathing-related issues, visit a pulmonologist. Patients with repeated lung/respiratory infections should see both a pulmonologist and immunologist (doctor who specializes in the immune system).

Gastroenterology (issues with the GI tract and liver)

Failure to Thrive: Any patient who isn’t meeting the normal growth rates should be evaluated and tracked.

Feeding issues

Constipation: Chronic constipation is typically managed with polyethylene glycol (Miralax). There is no difference between mobile and immobile SRS patients with chronic constipation.

Other findings (not statistically significant):

Diarrhea – may contain blood or mucous

GI inflammation: Crohn’s, colitis, or gastritis have been seen in some SRS individuals

GERD

Vomiting

Elevated liver transaminases (intermittent)

Urology

Some SRS patients have an unknown white-ish powder in their urine (which can also be seen through bladder ultrasounds). It’s not clear what’s causing it, but tests have shown the presence of calcium phosphate (apatite) AKA carbonate apatite.

Recommendation: Visit a urologist for further testing if this is the case. Routine urine tests during doctors visits is also recommended.

Kidneys (Nephrology)

Kidney stones (nephrolithiasis)

Tubulopathy – found in 3 patients

Debris in the bladder/white sediment in the urine (which has calcium phosphate/carbonate apatite)

Recommendation: Have repeated renal (kidney) ultrasounds over time to track the presence/absence of kidney stones & structural abnormalities

Creatinine level & kidney disease: Creatinine is a waste product produced by muscles from the breakdown of a compound called creatine. The kidney is responsible for removing creatinine from the body. High levels of creatinine can lead to kidney disease.

Because most SRS patients have low muscle mass, they often also have low creatinine levels to start out with. When getting testing for creatinine in SRS patients, the results might seem to be normal (as compared to the results of non-SRS patients) – this can be misleading because the creatinine level might actually be high in relation to the low muscle mass, and could be a sign of kidney disease.

When testing for creatine levels, be sure that you’re comparing it with the patient’s baseline level to accurately monitor kidney function

Blood (Hematology)

Iron Deficiency Anemia

Thrombocytopenia: Thrombocytopenia is a condition where you have a low blood platelet count. Having a low platelet count affects the body’s ability to form blood clots and stop bleeding.

This has been seen intermittently in some SRS patients & also in some newborns with SRS

If a baby is born with a diagnosis of SRS that was determined before birth (because of SRS family history), it’s recommended to check platelets (which isn’t a standard testing for newborns) to make sure he isn’t at risk of having thrombocytopenia

Endocrine

Osteoporosis – nearly all SRS patients have early onset osteoporosis & fractures

Recommendation: Get bone mineral density studies/DEXA scans early to test for and track bone health

Hypoglycemia – a condition where your blood sugar (glucose) level is lower than normal. Glucose is the body’s main source of energy.

Hyperglycemia – high levels of sugar (glucose) in the blood

This can be tracked by getting chemistry panels

Immunology: Findings of immune issues have been quite varied in SRS patients. We hope that continued studies will help us figure out if there is an immune component to SRS.

Multiple types of infections:

Otitis media (requiring PE tubes)

Sinusitis

Upper respiratory infections

Pneumonia

Urinary Tract Infections

Recurrent, intermittent, unexplained fevers

Abnormal immunoglobulins. Immunoglobulins are any class of proteins in the immune system, which function as antibodies.

Intravenous or subcutaneous immunoglobulin therapy (IVIG or SCIG) has been used as treatment

At least one SRS patient’s treatment includes immunosuppressants

Recommendation: Get comprehensive immune work ups to help understand the immune component of SRS

Often the work-up is negative except for abnormal immunoglobulins & abnormal response to pneumococcal vaccines

Development

SRS patients have shown different types of developmental delay and intellectual disabilities are varied.

Therapies that may help:

Speech therapy

Physical & Occupational therapy

Music, aquatic, equestrian therapy

Personal care options to help with SRS loved one:

Attendant care

Respite care

Nursing care

Next Step: Natural History Study

We are collecting data for the Natural History Study to help us better understand SRS through the medical history of SRS patients & families. The more information we gather for the NHS, the better we understand what is statistically significant and what directly correlates to SRS.As we collect and track the details of your child’s medical history, please know that you are helping us understand this ultra-rare disorder. The more information we collect from SRS patients, the better we understand SRS over time, which could help us find treatment options.