Monosomy 9P, otherwise known as Alfi's Syndrome or 9P-, is a rare chromosome anomaly affecting about one birth in five million. The disorder consists of mental retardation, sociable personality, trigonocephaly, mongoloid eyes, wide flat nasal bridge, anteverted nostrils, long upper lip, short neck, long digits mostly secondary to long middle phalanges, and predominance of whorls on fingers. Because of its extreme rarity, it is little-studied and little-known.