Mitochondrial Disease

In retrospect, it was clear from the moment Samantha Fargo was born six years ago that something was very wrong. At first, she was too weak to breast-feed. By five weeks, she could drink from a bottle, but she had such bad reflux (food backing up the esophagus from the stomach) that her parents, Justine and Bill Fargo of Medford, Mass., had to keep her semi-upright all the time. She didn't walk until she was 1 1/2, and she never had much energy.

British scientists say they have mastered a controversial technique using cloning technology to prevent some incurable inherited diseases by swapping DNA between two fertilized human eggs. Lead researcher Doug Turnbull of Newcastle University said this week that he hoped the first babies free from so-called mitochondrial diseases would be born within three years. The technique replaces mitochondrial DNA, which is passed down the maternal line. One in 6,500 children is born with serious diseases caused by malfunctioning mitochondrial DNA. The technique is a variation of the one used to clone Dolly the sheep in 1996.

There was a time when Lauren and Marshall Johnson waited for their only child to die. Jacob was just over a year old then, a towhead with bottomless blue eyes. His head flopped over his neck. His legs took him nowhere. He could not sit. Even Jacob's smiles, and tears, stayed trapped inside his soul. He was silent as a rag doll. Leigh's disease, a rare disorder of the central nervous system, had stolen nearly all of Jacob's muscle control.

In retrospect, it was clear from the moment Samantha Fargo was born six years ago that something was very wrong. At first, she was too weak to breast-feed. By five weeks, she could drink from a bottle, but she had such bad reflux (food backing up the esophagus from the stomach) that her parents, Justine and Bill Fargo of Medford, Mass., had to keep her semi-upright all the time. She didn't walk until she was 1 1/2, and she never had much energy.

British scientists say they have mastered a controversial technique using cloning technology to prevent some incurable inherited diseases by swapping DNA between two fertilized human eggs. Lead researcher Doug Turnbull of Newcastle University said this week that he hoped the first babies free from so-called mitochondrial diseases would be born within three years. The technique replaces mitochondrial DNA, which is passed down the maternal line. One in 6,500 children is born with serious diseases caused by malfunctioning mitochondrial DNA. The technique is a variation of the one used to clone Dolly the sheep in 1996.

Autistic children have a high incidence of defects in mitochondria, the "powerhouses" of cells, but it is not yet clear if those defects are a cause of the disorder or a byproduct of some more fundamental defect, UC Davis researchers said Tuesday. Mitochondria create energy for cellular metabolism and when they are dysfunctional, cells do not operate efficiently. That can be particularly disruptive for cells, such as brain cells, that have high energy demands. A lack of energy for brain cells during development could help explain why children with autism do not function properly.

IN ALL HER YEARS of tending sheep in the western reaches of the Navajo range, Lois Neztsosie had never seen anything so odd. New lakes had appeared as if by magic in the arid scrublands. Instead of hunting for puddles in the sandstone, she could lead her 100 animals to drink their fill. She would quench her own thirst as well, parting the film on the water's surface with her hands and leaning down to swallow. Despite the abundant water, an unexpected blessing, her flock failed to thrive.

There was a time when Lauren and Marshall Johnson waited for their only child to die. Jacob was just over a year old then, a towhead with bottomless blue eyes. His head flopped over his neck. His legs took him nowhere. He could not sit. Even Jacob's smiles, and tears, stayed trapped inside his soul. He was silent as a rag doll. Leigh's disease, a rare disorder of the central nervous system, had stolen nearly all of Jacob's muscle control.