FDA’s Menkes Approval Raises Newborn Screening Questions

The FDA’s first approval for Menkes disease is more than a rare-disease milestone. It also sharpens a public-health question: if treatment works best in the first weeks of life, how do we find affected babies before symptoms race ahead?

That question matters because Menkes disease is usually severe in infancy, and the new treatment is meant to replace copper before the disease causes lasting damage. The remaining challenge is screening: whether state systems can identify a tiny number of babies early, confirm the result quickly, and get families to care without delay.

Menkes disease, in plain language

Menkes disease is a genetic disorder that interferes with the body’s ability to absorb and distribute copper. Copper is needed for normal brain and body development, and when it does not move where it should, children can develop seizures, feeding problems, poor growth, low muscle tone, developmental delay, and unusual hair changes in infancy, according to MedlinePlus and the FDA.

The condition is inherited in an X-linked pattern and is more common in boys. In classic Menkes disease, symptoms usually begin early in life, and without treatment many children do not survive past early childhood.

What the FDA approved

On January 12, 2026, the FDA approved Zycubo, or copper histidinate injection, as the first treatment for pediatric patients with Menkes disease. The agency said the drug provides copper in a form that bypasses the intestinal transport defect linked to the disorder.

The approval was based on two open-label, single-arm trials and comparisons with untreated external control groups. The FDA said the analysis included 66 treated patients and 17 untreated patients, most of whom were from the United States. Children who began treatment within four weeks of birth had a 78% lower risk of death than untreated patients, and nearly half of early-treated patients survived beyond six years. Some survived more than 12 years. Children who started treatment later than four weeks after birth also appeared to benefit.

That is encouraging, but it is not the same as a randomized trial. For a very rare disease, that kind of study may be hard or impossible to run, so the evidence relies on small numbers and external comparisons rather than a classic placebo-controlled design.

Safety monitoring also matters. The FDA said the most common side effects included infections, respiratory problems, seizures, vomiting, fever, anemia, and injection-site reactions. Because copper can accumulate in the body, patients receiving Zycubo should be closely monitored for potential toxicity.

Why newborn screening is part of the story

CDC says newborn screening laboratories support state programs with quality-control dried blood spot materials, technical assistance, and training. The goal is to keep screening accurate and timely so babies with serious but treatable conditions can be identified and treated early.

That timing is the key issue for Menkes disease. MedlinePlus notes that children often show symptoms early in infancy, which means diagnosis and treatment may need to happen before a family or clinician fully recognizes the pattern.

That is why the screening conversation is changing. A disease that once seemed mostly diagnosable after symptoms now has a treatment window that may begin before obvious damage has occurred.

What the February genomics study adds

A recent peer-reviewed study indexed in PubMed explored whole-genome sequencing from dried blood spots for Menkes disease and other actionable inherited disorders. The researchers reported that they could extract DNA from dried blood spots and detect known ATP7A variants in their study set, suggesting that genome-based screening could someday complement current newborn-screening methods.

But the study was a feasibility and validation project, not proof that nationwide newborn sequencing is ready for routine use. It does not settle questions about false positives, follow-up capacity, costs, turnaround time, equity, or whether every state could implement such testing consistently.

The bigger uncertainty

The FDA approval makes the case for early detection much stronger. It does not, by itself, solve the public-health problem of reaching babies in time.

For ultra-rare diseases like Menkes, the open questions are practical: Can screening be accurate enough? Can confirmatory testing happen fast enough? Will families in every region get the same access to follow-up and treatment? And can health systems support a pathway that may be lifesaving for a small number of babies but complex to run at scale?

What readers can do

If a family has a known history of Menkes disease or another inherited disorder, it is reasonable to ask a clinician or genetic counselor about carrier testing and newborn-screening options before a pregnancy or after birth. If an infant has feeding problems, unusual hair changes, low muscle tone, seizures, or developmental concerns in the first months of life, those signs deserve prompt medical attention.

For most readers, the takeaway is simpler: a rare-disease drug approval can be important even when the affected population is very small, because it can change what early diagnosis is worth and how urgently screening systems need to work.

Sources

Editorial note: Weence articles are researched from cited public-health, medical, regulatory, journal, and reputable news sources and may be drafted with AI assistance. They are checked for source support, clarity, and safety guardrails before publication.

This article is for general informational purposes only and is not medical advice. Research findings can be early or incomplete, and health guidance can change. Always talk with a qualified healthcare professional about personal symptoms, diagnosis, medications, vaccines, screenings, or treatment decisions. If you think you may have a medical emergency, call emergency services right away.