It's all in the genes

Families with knowledge of rare metabolic disorders are fast-tracked for newborn screening, writes SYLVIA THOMPSON

GAVIN AND EMER Butler are enjoying the playfulness of their 18-month-old baby daughter, Alicia, and her big brother, Mark. Baby Alicia is walking, saying a few words and showing a curious interest in the world around her.

Her parents are acutely aware that this might not have been the case as the first days of Alicia’s life were extremely traumatic when what first appeared to be a case of jaundice resulted in a diagnosis of the rare inherited disorder, classical galactocaemia(see panel).

Following a normal birth, baby Alicia and her mother, Emer, were discharged from hospital four days afterwards. The public health nurse visited them at home on day four and day five and noticed that the jaundice was changing colour. She suggested they bring baby Alicia back to the Coombe Hospital for a check-up. “We had also noticed that she was very lethargic and we had to wake her up for feeding,” says Gavin Butler.

Within hours of arriving at the hospital, Alicia had a seizure. Classical galactosaemia was immediately considered to be the cause and Alicia was put on a specialised soya-based formula feeds while a blood sample was sent for testing (Alicia had the heel prick blood test on day four but the results hadn’t arrived back at that time). Her liver function was found to be poor and she was given a blood transfusion.

At this point, Gavin remembered that his cousin had galactosaemia and told the doctors. “Prior to this, I thought that family history only included fathers, mothers, aunts, uncles and grandparents, and not cousins,” he explains.

As it turned out, both Gavin and Emer were carriers of galactosaemia, which means that any of their children has a one in four chance of having the condition. Baby Alicia did well on the specialised formula feeding for classical galactosaemia. She remained in the ICU unit for two weeks and spent another week in the Special Care Unit at the Coombe. Gavin is so grateful to the staff at the hospital that he has organised a fundraising event for the neonatal unit there.

Dr Margaret Sheridan-Pereira, the paediatrician dealing with the Butlers says that the case highlights the importance of knowing the medical conditions in your extended family during pregnancy. “People don’t talk about their family history as much now and it is often only when a baby is diagnosed with a condition that the parents discover other family members had the condition,” she says.

Alicia’s condition continues to be monitored as there are other unpredictable long-term effects associated with galactosaemia. “She had EEG and MRI scans at Our Lady’s Hospital for Children in Crumlin when she was one week old and again when she was six months old. She had intensive physiotherapy until she was one,” explains Gavin. “Now, we only have to do speech therapy with her.”

Emer adds: “It’s so sad that babies can be left with brain damage and serious development problems all because of the milk they are given. The condition is manageable once you know it’s there, but severe and life-threatening if you don’t. We feel very lucky that Alicia escaped it.”

Prof Philip Mayne, the director of the National Newborn Screening laboratory, stresses that families with knowledge of these rare metabolic disorders are fast-tracked for newborn screening – and any babies born to them are put on the specialised diet (for the suspected condition) until blood test results come back.

A fundraising concert featuring Abbaesque, The Classic Beatles and an Elvis tribute act (in which Gavin Butler is the trumpet player) takes place at the Olympia Theatre in Dublin, on Sunday, March 20th. All proceeds go to the Neonatal Intensive Care Unit in the Coombe Women and Infants University Hospital. Tickets €25. Tel: 01-6793323.

The heel prick test: what's included?

All babies born in Ireland are offered the heel prick blood test 72-120 hours after their birth. The blood is then sent to the National Newborn Screening laboratory at the Children's University Hospital in Temple Street, Dublin, to check for the presence of the following five rare, inherited conditions.

Phenylketonuria (PKU) is an inherited condition caused by the lack of the enzyme, phenylalanine hydroxylase which normally breaks down the amino acid (a building block for protein) phenylalanine into tyrosine. A high phenylalanine level in the blood may damage the nerve cells in the brain. Early detection results in the baby being given specialised formula feeds which regulate the amino acids imbalance. Treatment with this diet is for life.

Classical galactosaemia is an inherited condition caused by the lack of an enzyme which metabolises galactose, one of the two sugars which make up lactose in human and cow's milk. If not detected early, the disorder can be life-threatening due to the complications caused by the build-up of galactose in the blood. Specialised formula feeds based on soya prevent early symptoms, but may not prevent some longer term complications.

Maple Syrup Urine Disease (MSUD) is an inherited life-threatening condition which involves the build-up of three amino acids in the blood. If a formula feed without the offending amino acids is given to the baby as soon as possible after birth, he/she will develop normally. The diet must be continued throughout life.

Homocystinuria (HCU) is caused by the build-up of homocysteine in the blood due to the lack of an enzyme which normally metabolises it into an amino acid. Excessive homocysteine can result in blood clots and heart attacks in later life, if not treated. Most, but not all, babies with this condition are detected with newborn screening. Once detected, a specialised formula is prescribed.

Congenital Hypothyroidism (CHT) is due to the failure of the thyroid gland to develop or to produce thyroxine from birth. This condition can be easily treated with thyroxine tablets which, in most cases, are required for life.

Screening for cystic fibrosis will be included to the National Newborn Screening programme later this year and more conditions will probably be added in the future.

See nnsp.ie for the incidence of the conditions mentioned above