This study describes the clinical and radiological features of 105 individuals with nevoid basal cell carcinoma syndrome (NBCC), also known as Gorlin syndrome. The syndrome is an autosomal dominant disorder linked to 9q22.3-q31, caused by mutations in the PTC gene, which is the human homologue of the Drosophila patched gene. The syndrome is characterized by multiple basal cell carcinomas (BCCs), jaw keratocysts, palmar/plantar pits, spine and rib anomalies, and calcification of the falx cerebri. The study reviewed data from 105 affected individuals examined at the NIH since 1985, including 48 males and 57 females aged 4 months to 87 years. Eighty percent of whites and 38% of African-Americans had at least one BCC, with the first tumor occurring at a mean age of 23 and 21 years, respectively. The number of BCCs ranged from 1 to >1,000 in whites and 1 to 3 in African-Americans. Jaw cysts occurred in 78/105 individuals, with the first tumor occurring in 80% by age 20. Palmar pits and plantar pits were seen in 87% of affected individuals. Ovarian fibromas were diagnosed in 17% of affected females. Medulloblastoma occurred in 4 patients. Physical findings included coarse face, macrocephaly, hypertelorism, frontal bossing, pectus deformity, and Sprengel deformity. Radiological signs included calcification of the falx cerebri in 65%, of the tentorium cerebelli in 20%, bridged sella in 68%, bifid ribs in 26%, hemivertebrae in 15%, and flame-shaped lucencies in 30%. Several traits previously considered components of the syndrome were not found to be significantly increased in affected individuals. The study delineates the frequency of clinical and radiological anomalies in NBCC in a large population of US patients and discusses guidelines for diagnosis and management. The study found that the frequency of BCCs was higher in whites (80%) compared to African-Americans (38%). The study also found that the frequency of palmar pits was higher in the NIH population compared to the UK group. The study found that the frequency of falx calcification was higher in the Australian study compared to the NIH study. The study found that the frequency of medulloblastoma was higher in the UK population compared to the NIH population. The study found that the frequency of ovarian fibromas was higher in the NIH population compared to the UK population. The study found that the frequency of jaw cysts was higher in the NIH population compared to theThis study describes the clinical and radiological features of 105 individuals with nevoid basal cell carcinoma syndrome (NBCC), also known as Gorlin syndrome. The syndrome is an autosomal dominant disorder linked to 9q22.3-q31, caused by mutations in the PTC gene, which is the human homologue of the Drosophila patched gene. The syndrome is characterized by multiple basal cell carcinomas (BCCs), jaw keratocysts, palmar/plantar pits, spine and rib anomalies, and calcification of the falx cerebri. The study reviewed data from 105 affected individuals examined at the NIH since 1985, including 48 males and 57 females aged 4 months to 87 years. Eighty percent of whites and 38% of African-Americans had at least one BCC, with the first tumor occurring at a mean age of 23 and 21 years, respectively. The number of BCCs ranged from 1 to >1,000 in whites and 1 to 3 in African-Americans. Jaw cysts occurred in 78/105 individuals, with the first tumor occurring in 80% by age 20. Palmar pits and plantar pits were seen in 87% of affected individuals. Ovarian fibromas were diagnosed in 17% of affected females. Medulloblastoma occurred in 4 patients. Physical findings included coarse face, macrocephaly, hypertelorism, frontal bossing, pectus deformity, and Sprengel deformity. Radiological signs included calcification of the falx cerebri in 65%, of the tentorium cerebelli in 20%, bridged sella in 68%, bifid ribs in 26%, hemivertebrae in 15%, and flame-shaped lucencies in 30%. Several traits previously considered components of the syndrome were not found to be significantly increased in affected individuals. The study delineates the frequency of clinical and radiological anomalies in NBCC in a large population of US patients and discusses guidelines for diagnosis and management. The study found that the frequency of BCCs was higher in whites (80%) compared to African-Americans (38%). The study also found that the frequency of palmar pits was higher in the NIH population compared to the UK group. The study found that the frequency of falx calcification was higher in the Australian study compared to the NIH study. The study found that the frequency of medulloblastoma was higher in the UK population compared to the NIH population. The study found that the frequency of ovarian fibromas was higher in the NIH population compared to the UK population. The study found that the frequency of jaw cysts was higher in the NIH population compared to the