Metabolic Genetics Clinic

My newborn received an abnormal screen. What do I do?

newborn test

At the Metabolic Genetics Clinic, we specialize in the diagnosis and treatment of children and adults with inherited metabolic disorders, also known as “inborn errors of metabolism.” 

Metabolism refers to all the chemical reactions that take place in our body to break down food to make proteins and other molecules. Our bodies use these proteins and molecules to function, release energy and convert excess nitrogen into waste products excreted in urine. Metabolic diseases occur when these chemical processes are interrupted, and are often due to enzyme deficiencies caused by errors in single genes. There are hundreds of inherited metabolic diseases. Most people with metabolic diseases begin experiencing symptoms in the newborn period or childhood, but in some, the disease becomes apparent in adulthood. 

Many metabolic diseases are treatable. Early diagnosis and treatment may prevent permanent organ damage and death. Treatments vary based on the specific disease and often involve modification of diet and supplementation with specific medications, as well as preemptive inpatient care during infections. Other therapies include enzyme replacement therapy, hematopoietic stem cell transplantation, and organ transplantation gene therapy.

In the Metabolic Genetics Clinic, we evaluate patients with a variety of symptoms, including:

  • Abnormal newborn screen
  • Recurrent unexplained illness with dehydration and acidosis
  • Recurrent hypoglycemia
  • Altered mental status
  • Liver disease
  • Feeding intolerance, recurrent vomiting
  • Failure to thrive
  • Hypotonia
  • Progressive deterioration of neurologic function        
  • Epilepsy
  • Muscle weakness, muscle breakdown

We diagnose and treat patients who have a wide range of metabolic conditions including:

  • Carbohydrate disorders
    • Galactosemia, hereditary fructose intolerance, glycogen storage diseases
  • Amino acid disorders
    • Phenylketonuria (including metabolic management of PKU prior to and during pregnancy), tyrosinemia, homocystinuria, maple syrup urine disease
  • Fatty acid oxidation defects
    • Medium and long chain fatty acid oxidation defects (MCADD, LCHADD, VLCADD), carnitine disorders
  • Organic acidemias
    • Methylmalonic acidemia, propionic acidemia, biotinidase deficiency, glutaric acidurias, isovaleric academia, vitamin B12 metabolism disorders
  • Urea cycle disorders
    • Ornithine transcarbamylase deficiency, citrullinemia, argininosuccinic aciduria and others
  • Mitochondrial diseases
    • MELAS, MERRF, NARP, Leigh disease, Barth syndrome and others
  • Peroxisomal disorders 
    • X-linked Adrenoleukodystrophy, Zellweger spectrum disorders, Refsum disease and others
  • Lysosomal storage disorders
    • Gaucher disease, Fabry disease, mucopolysaccharidoses, Pompe disease and others


Appointment Scheduling: 410-955-3071
Metabolic Emergencies ONLY: To reach a member of the Metabolic Genetics Clinic on-call team, patients and health care providers should call 667-239-0265 (available 24 hours/day, 7 days a week). Metabolic emergencies may include high ammonia, metabolic acidosis, abnormal newborn screenings and pregnancy in patients with phenylketonuria or other inborn metabolic diseases. To request to transfer a patient who is an inpatient at another hospital to a hospital in the Johns Hopkins Health System, call the Hopkins Access Line.

Our Team

Our team consists of geneticists specialized in metabolic disorders, two genetic counselors, a nurse manager, a metabolic dietitian and a clinic coordinator. Our outpatient Metabolic Genetics Clinic runs three days a week. To ensure timely and accurate diagnosis, we work closely with the Biochemical Genetics Laboratory at the Kennedy Krieger Institute. Our on-call team of metabolic doctors is available to our patients and families 24 hours a day, seven days a week. When our pediatric metabolic patients need inpatient hospital care, we admit them to Johns Hopkins Children’s Center under our own Metabolic Inpatient Service and serve as their primary inpatient caregiver team. When our adult metabolic patients need inpatient hospital care, we consult closely with the medical, surgical, gynecologic-obstetric or neurologic teams that are managing their care. Our team works with specialists throughout Johns Hopkins Medicine to ensure that you receive expert, coordinated care, including neurology, ophthalmology, audiology, cardiology, and transplant medicine.


Ada Hamosh, M.D., M.P.H.

  • Dr. Frank V. Sutland Professor of Pediatric Genetics
  • Professor of Genetic Medicine
  • Professor of Pediatrics

Expertise: Genetics, Genetics and Inherited Diseases, Medical Genetics, Medical Genetics-Inherited Disorders


Hind Al Sharhan, M.B.B.Ch.

Assistant Professor of Genetic Medicine

Hind Al Sharhan

Nutrition Specialists

Celide Barnes Koerner, M.S., R.N.

Celide Barnes Koerner is a senior research nurse and program coordinator with the Johns Hopkins Department of Genetic Medicine, with over 35 years of clinical experience treating children and adults with inborn errors of metabolism. She holds a master’s degree in nutrition from Tufts University, which was combined with a clinical internship at the Frances Stern Nutrition Center. She later completed her bachelor of science degree in nursing from The Johns Hopkins University. Her area of special interest is maternal phenylketonuria.

Celide Koerner

Genetic Counselors

Krista Schatz, M.S., C.G.C.

Krista Schatz is a board-certified genetic counselor. She provides genetic counseling services to pediatric and adult patients and their families in the Metabolic Genetics Clinic in the Department of Genetic Medicine at The Johns Hopkins Hospital, where she focuses on mitochondrial disorders and lysosomal storage disorders, including abnormal newborn screening. She attended the Case Western Reserve University Genetic Counseling Program, where she graduated with a master’s degree in genetic counseling.

Krista Schatz

Kelsey Stauff Guthrie, M.G.C., C.G.C.

Kelsey Guthrie is a certified genetic counselor. She provides genetic counseling to pediatric and adult patients and their families in the Metabolic Genetics Clinic in the Department of Genetic Medicine at The Johns Hopkins Hospital. She graduated from University of Maryland with a master’s degree in genetic counseling. She completed her undergraduate training at the University of Maryland, majoring in secondary education and biology. She is a member of the American Board of Genetic Counseling, the National Society of Genetic Counselors and the Maryland and D.C. Society of Genetic Counselors.

Kelsey Stauff Guthrie

Administrative Staff

Callie Ferguson

Dana Goins
Clinic Manager

Crystal Thomas
Medical Office Coordinator