Nocturnal enuresis, or nightly bedwetting in children more than 7 years of age, affects about 10% of 7-year-old children, with a wide range of frequencies between populations. The affliction is often linked to major social maladjustments and occupies considerable time in general medical practice. From the age of 7, there is a spontaneous cure rate of 15% per year, such that few remain affected after the age of 16 years. There are 2 types of nocturnal enuresis: type I, the primary form (PNE), with at least 3 nightly episodes in children older than 7 years, where the child has always had the disorder, and type II, or secondary type, where the child has been dry for at least 6 months but enuresis has recurred (summary by Eiberg et al., 1995). Genetic Heterogeneity of Nocturnal Enuresis ENUR1 has been mapped to chromosome 13q, and ENUR2 has been mapped to chromosome 12q.

Nocturnal enuresis, or nightly bedwetting in children more than 7 years of age, affects about 10% of 7-year-old children, with a wide range of frequencies between populations. The affliction is often linked to major social maladjustments and occupies considerable time in general medical practice. From the age of 7, there is a spontaneous cure rate of 15% per year, such that few remain affected after the age of 16 years. There are 2 types of nocturnal enuresis: type I, the primary form (PNE), with at least 3 nightly episodes in children older than 7 years, where the child has always had the disorder, and type II, or secondary type, where the child has been dry for at least 6 months but enuresis has recurred (summary by Eiberg et al., 1995). Genetic Heterogeneity of Nocturnal Enuresis ENUR1 has been mapped to chromosome 13q, and ENUR2 has been mapped to chromosome 12q.

Nocturnal enuresis where the child has been dry for at least 6 months but enuresis has recurred.

Patients with familial renal glucosuria have decreased renal tubular resorption of glucose form the urine in the absence of hyperglycemia and any other signs of tubular dysfunction. Glucosuria in these patients can range from less than 1 to over 150 g/1.73 m(2) per day (Santer and Calado, 2010).

Osteogenesis imperfecta (OI) is a connective tissue disorder characterized by bone fragility and low bone mass. Due to considerable phenotypic variability, Sillence et al. (1979) developed a classification of OI subtypes based on clinical features and disease severity: OI type I, with blue sclerae (166200); perinatal lethal OI type II, also known as congenital OI (166210); OI type III, a progressively deforming form with normal sclerae (259420); and OI type IV, with normal sclerae (166220). Most cases of OI are autosomal dominant with mutations in 1 of the 2 genes that code for type I collagen alpha chains, COL1A1 (120150) and COL1A2 (120160). Martinez-Glez et al. (2012) described osteogenesis imperfecta type XIII, an autosomal recessive form of the disorder characterized by normal teeth, faint blue sclerae, severe growth deficiency, borderline osteoporosis, and an average of 10 to 15 fractures a year affecting both upper and lower limbs and with severe bone deformity.

ADNP-related disorder is characterized by hypotonia, severe speech and motor delay, mild-to-severe intellectual disability, and characteristic facial features (prominent forehead, high anterior hairline, wide and depressed nasal bridge, and short nose with full, upturned nasal tip) based on a cohort of 78 individuals. Features of autism spectrum disorder are common (stereotypic behavior, impaired social interaction). Other common findings include additional behavioral problems, sleep disturbance, brain abnormalities, seizures, feeding issues, gastrointestinal problems, visual dysfunction (hypermetropia, strabismus, cortical visual impairment), musculoskeletal anomalies, endocrine issues including short stature and hormonal deficiencies, cardiac and urinary tract anomalies, and hearing loss.

Myofibrillar myopathy-7 (MFM7) is an autosomal recessive muscle disorder characterized by early childhood onset of slowly progressive muscle weakness that primarily affects the lower limbs and is associated with joint contractures (summary by Straussberg et al., 2016). For a general phenotypic description and a discussion of genetic heterogeneity of myofibrillar myopathy, see MFM1 (601419).

Marbach-Schaaf neurodevelopmental syndrom (MASNS) is characterized by global developmental delay with speech delay and behavioral abnormalities, including autism spectrum disorder and ADHD. Affected individuals also show movement disorders, such as dyspraxia and apraxia. More variable features include high pain tolerance, sleep disturbances, and variable nonspecific dysmorphic features (summary by Marbach et al., 2021).