Alström Syndrome Diagnosis: Tests, Timeline & Next Steps

A diagnosis of Alström Syndrome usually starts with one or two clues — a baby who can't tolerate light, eyes that wobble, an unexplained heart problem in infancy — and ends with a genetic test confirming changes in the ALMS1 gene. The path between those two points can take months or years, and it involves several specialists. This guide walks you through every step so you know what to expect, what questions to ask, and how to keep the process moving.

Alström Syndrome (ALMS) is an ultra-rare genetic condition that affects multiple body systems over time. It is caused by changes in both copies of the ALMS1 gene and is inherited in an autosomal recessive pattern, which means both parents carry one altered copy.¹ The condition is progressive — symptoms unfold in waves rather than appearing all at once — and the timing varies a lot from one child to another.

The earliest signs that bring families to a doctor are usually:

• Severe light sensitivity (photophobia) in babies — the child squints or cries in normal indoor light
• Wobbly eye movements (nystagmus) appearing in the first 15 months
• Unexplained heart failure (dilated cardiomyopathy) in infancy, which affects more than 60% of children with Alström²
• Hearing loss that emerges in the first decade in around 70% of affected children³

Less obvious signs may appear over time — early childhood weight gain, recurrent chest infections, developmental delays, or difficulty in school as vision and hearing change.

Step 1: First medical contacts

Most families start with their pediatrician or family doctor, often because of the visual symptoms or the heart concerns. From there, the journey typically branches to specialists in:

• Pediatric ophthalmology — for the eye signs
• Pediatric cardiology — if the baby has signs of heart problems
• ENT or audiology — once hearing loss is suspected

A 2024 report from Alström Syndrome UK found that families often attend dozens of appointments before the syndrome is recognized.⁴ This is changing — the average age of diagnosis in the UK dropped from 20 years in 2018 to about 7 years in 2022 — but a diagnostic delay is still common, especially when only one organ system is involved at first.

Step 2: Eye tests that point toward Alström

Pediatric ophthalmologists use several tests to characterize the visual problem:

• Electroretinogram (ERG) measures the electrical response of the retina to flashes of light. In Alström, the ERG shows reduced or absent cone responses early on, and rod responses decline over time.⁵
• Optical coherence tomography (OCT) images the retinal layers and shows progressive thinning.
• Fundus examination may look normal in young children even when the ERG is abnormal — that mismatch can be a clue.
• Visual fields and visual acuity testing track how vision changes.

The pattern of cone-rod dystrophy together with severe early-life photophobia is highly suggestive of Alström, especially when paired with one of the systemic features below.

Step 3: Heart tests

If a baby has signs of heart failure or unexplained breathlessness:

• Echocardiogram is the first imaging study and usually shows a dilated left ventricle with reduced function.
• Cardiac MRI may be added later for more detail.
• EKG and 24-hour Holter monitor screen for arrhythmias.

Infantile dilated cardiomyopathy is a hallmark of Alström, but it isn't unique to it — other causes (viral myocarditis, mitochondrial disease, other genetic cardiomyopathies) need to be considered. That's one reason genetic testing matters so much.

Step 4: Recognizing the multisystem pattern

The clinical diagnostic criteria for Alström are stratified by age. They include "major" criteria (such as ALMS1 mutations and a family history) and "minor" criteria (specific organ findings) at three age bands: birth–2 years, 3–14 years, and 15+.⁶ A clinical geneticist or a multidisciplinary Alström clinic can apply these criteria formally.

You don't need to wait for a perfect criteria match to test, though. If a child has cone-rod dystrophy plus any one of the systemic features (heart, hearing, obesity, diabetes, kidney, liver), most genetics specialists will order an ALMS1 panel.

Step 5: Genetic testing

The diagnosis is confirmed by finding two pathogenic (disease-causing) variants in the ALMS1 gene. There are several ways to test:

• *Targeted ALMS1 sequencing* — the most direct route when Alström is strongly suspected
• A multi-gene panel for retinal dystrophies, ciliopathies, or pediatric cardiomyopathies — useful when the picture isn't clear-cut
• Whole-exome sequencing — used when targeted panels haven't found an answer

A test result might say something like "two pathogenic variants identified in ALMS1 (compound heterozygous)" — that confirms the diagnosis. A "variant of uncertain significance" or only one variant found means more work is needed.⁷

Step 6: After the genetic result

Once the diagnosis is confirmed, the next 30 days are usually about assembling a care team and getting baseline studies for the systems that aren't yet symptomatic. That's covered in our first steps after diagnosis guide and our overview of the Alström care team.

Three patterns lead to delay:

1. Single-system presentation. A baby with isolated dilated cardiomyopathy, or a toddler with isolated retinal disease, may not look like a syndromic case until a second system is involved. 2. Misdiagnosis as a similar condition. Alström overlaps significantly with Bardet-Biedl Syndrome, Usher Syndrome, Leber Congenital Amaurosis, and other ciliopathies. The differences only become obvious over time. 3. Limited specialist familiarity. With around 1,200 known cases worldwide, most pediatricians and many specialists have never seen an Alström case. Asking the right question at the right time is hard.⁸

If you suspect Alström and your team isn't moving toward genetic testing, you can ask directly: "Could this be Alström Syndrome — and could we order an ALMS1 panel?"

Once ALMS1 mutations are confirmed, the 2020 international consensus guidelines recommend baseline studies in every system Alström can affect, plus a regular surveillance schedule going forward. These typically include:⁹

• Echocardiogram, EKG, and cardiac MRI as appropriate
• Liver and kidney function tests, and abdominal ultrasound
• Fasting glucose, HbA1c, lipids, and insulin
• Audiology assessment with audiogram, OAE, and tympanometry
• Ophthalmology workup with ERG, OCT, and visual fields
• Spinal X-ray if scoliosis is suspected
• Sleep study if there are symptoms of obstructive sleep apnea

We cover the surveillance schedule in detail in Cardiac monitoring schedule for Alström, Annual audiology tests for Alström, and Eye care routine for Alström Syndrome.

Push for an Alström evaluation if your child has any of the following combinations:

• Photophobia or nystagmus in infancy + unexplained heart failure
• Cone-rod dystrophy on ERG + early-onset childhood weight gain
• Confirmed dilated cardiomyopathy + a sibling with retinal disease
• A diagnosis of Bardet-Biedl Syndrome that doesn't quite fit (no polydactyly, intelligence within typical range, severe insulin resistance)
• Hearing loss appearing in the first decade + any of the above

If your team isn't familiar with Alström, ask for a referral to a clinical geneticist or to one of the Alström Centers of Excellence.

• What Is Alström Syndrome? Simple Family Guide
• Alström Syndrome Symptoms by Stage
• Early Signs of Alström Syndrome in Babies
• Why Alström Syndrome Is Often Misdiagnosed
• The Diagnostic Journey for Alström Syndrome
• Genetic Testing for Alström Syndrome: A Parent's Guide
• How Is Alström Syndrome Inherited?

April 30, 2026.