NDP gene mutations in 14 French families with Norrie disease

Abstract

Norrie disease is a rare X‐inked recessive condition characterized by congenital blindness and occasionally deafness and mental retardation in males. This disease has been ascribed to mutations in the NDP gene on chromosome Xp11.1. Previous investigations of the NDP gene have identified largely sixty disease‐causing sequence variants. Here, we report on ten different NDP gene allelic variants in fourteen of a series of 21 families fulfilling inclusion criteria. Two alterations were intragenic deletions and eight were nucleotide substitutions or splicing variants, six of them being hitherto unreported, namely c.112C>T (p.Arg38Cys), c.129C>G (p.His43Gln), c.133G>A (p.Val45Met), c.268C>T (p.Arg90Cys), c.382T>C (p.Cys128Arg), c.23479‐1G>C (unknown). No NDP gene sequence variant was found in seven of the 21 families. This observation raises the issue of misdiagnosis, phenocopies, or existence of other X‐linked or autosomal genes, the mutations of which would mimic the Norrie disease phenotype. © 2003 Wiley‐Liss, Inc.

Deletion of MAOA and MAOB in a male patient causes severe developmental delay, intermittent hypotonia and stereotypical hand movements

“…To date, over 70 pathogenic NDP mutations have been identified. [8][9][10] Accessory phenotypes in 'classical' ND include progressive sensorineural deafness in approximately one-third of cases and some degree of intellectual disability, autism or psychosis in over 50% of cases. 11 Atypical ND patients with a contiguous deletion of NDP and both MAO genes present with a more severe neurological involvement, with profound psychomotor and verbal deficits.…”

A novel missense mutation in the NDP gene in a child with Norrie disease and severe neurological involvement including infantile spasms

“…The NDP gene, located on chromosome Xp11.1 [Bleeker‐Wagemakers et al, 1985], was identified by positional cloning by two groups [Berger et al, 1992; Chen et al, 1992]. Extensive investigations of the two coding exons of the NDP gene have led to the identification of at least 70 disease causing mutations in ND patients [Schuback et al, 1995; Royer et al, 2003; Riveiro‐Alvarez et al, 2005].…”

Review Studies of GJB2 Gene in Patients with Hearing Impairment in Pakistan

“…The anomalies caused by Norrie disease (a syndrome associated with X-linked HL) include bilateral blindness, bilateral sensorineural HL, mental retardation and microphthalmia [96,97]. Poor growth, microcephaly, seizures, delay in sexual maturity, cardiovascular problems, pulmonary arterial hypertension and psychomotor retardation like complex symptoms are also seen in some patients [98][99][100][101][102][103][104][105]. Patients affected by AR Biotinidase deficiency syndrome shows the signs like deafness, hair loss, seizures, emesis, skin rashes and acidosis.…”