Electroretinography and diagnosis of the Laurence-Moon-Bardet-Biedl syndrome in childhood.

The cases of two children affected from LMBB syndrome are reported. The first child was six years old, suffering from obesity and mild mental retardation; the other was two years old, suffering from hexadactyly and obesity. In both children the suspected diagnosis of LMBB syndrome was verified by the electroetinographic evidence of a tapetoretinal degeneration although the fundi were atypical. A third child, the younger brother of the second case, presented an atypical pigmentation of the retina and the electroretinographic changes of a tapeto-retinal degeneration. Since tapeto-retinal degeneration, which is the most common of the main signs of the syndrome, is not always recognized by ophthalmoscopy in early childhood, the clinical value of electroretinography in making an early diagnosis is emphasized.