No abstract

With an incidence of 1 in 3,000, neurofibromatosis type 1 (NF1), or von Recklinghausen disease, is one of the most common genetic disorders encountered by primary care physicians. NF1 is a multisystem disease that affects more than one million people worldwide (more than 80,000 in the United States). Although most pediatricians have patients with NF1 in their practices, many affected individuals go undiagnosed as children. This article is intended to facilitate the diagnosis and management of young patients with NF1.

FG syndrome is a rare X-linked recessive form of mental retardation, first described by Opitz and Kaveggia in 1974 in five related males with mental retardation, disproportionately large heads, imperforate anus, and congenital hypotonia. Partial agenesis of the corpus callosum was noted in at least one of the initial cases and has been seen in a number of subsequently-reported cases. The associated congenital hypotonia with joint hyperlaxity tends to progress to contractures with spasticity and unsteady gait in later life. The presence of subtle facial abnormalities and the characteristic behavior in midchildhood facilitate diagnosis at this age, particularly when there are other affected male relatives in the maternal family. Recently, Briault et al. [1997] mapped a gene for FG syndrome to the Xq12-q21.31 region. We describe three additional families (six additional patients) with FG syndrome on whom we have conducted linkage analysis. Our findings support the localization of a gene for the FG syndrome in Xq12-q21. In addition, we have noted skewed X-inactivation in carrier females, as well as new associated findings in affected males of sagittal craniosynostosis and split hand malformation.

FG syndrome is a rare X-linked recessive form of mental retardation, first described by Opitz and Kaveggia in 1974 in five related males with mental retardation, disproportionately large heads, imperforate anus, and congenital hypotonia. Partial agenesis of the corpus callosum was noted in at least one of the initial cases and has been seen in a number of subsequently-reported cases. The associated congenital hypotonia with joint hyperlaxity tends to progress to contractures with spasticity and unsteady gait in later life. The presence of subtle facial abnormalities and the characteristic behavior in midchildhood facilitate diagnosis at this age, particularly when there are other affected male relatives in the maternal family. Recently, Briault et al. [1997] mapped a gene for FG syndrome to the Xq12-q21.31 region. We describe three additional families (six additional patients) with FG syndrome on whom we have conducted linkage analysis. Our findings support the localization of a gene for the FG syndrome in Xq12-q21. In addition, we have noted skewed X-inactivation in carrier females, as well as new associated findings in affected males of sagittal craniosynostosis and split hand malformation.

We present two unrelated cases with a similar pattern of multiple congenital anomalies including limb shortening, long bone angulation, and cervical lymphocele. We believe these cases to represent additional examples of a syndrome first described by Cumming et al. (1986), and by Urioste et al. (1991) and Ming et al. (1997).