Question: Which is the neurodevelopmental disorder associated to mutations in the X- linked gene mecp2?

Context:
Rett syndrome is caused by mutations in the gene coding for methyl CpG-binding protein 2 (MeCP2).
Rett syndrome is one of the most common causes of complex disability in girls. It is characterized by early neurological regression that severely affects motor, cognitive and communication skills, by autonomic dysfunction and often a seizure disorder. It is a monogenic X-linked dominant neurodevelopmental disorder related to mutation in MECP2, which encodes the methyl-CpG-binding protein MeCP2.
Recently, this syndrome has been associated with mutations of the MECP2 gene, a transcriptional repressor of still unknown target genes. Here we report a detailed mutational analysis of 62 patients from UK and Italian archives, representing the first comparative study among different populations and one of the largest number of cases so far analyzed.
Out of the 365 cases, 315 had MECP2 gene mutations and 3 had de novo CDKL5 gene mutations. No patients had FOXG1 mutation.
Mutations were detected in ≈ 70% of classic and ≈ 21% of variant RTT, respectively. Amongst MR cases, 2.1% carried MECP2 mutations.
Mutations in the MECP2 gene were detected in 13 of the 20 (65 percent) RS patients.
This multicenter investigation into the phenotypic correlates of MECP2 mutations in Rett syndrome has provided a greater depth of understanding than hitherto available about the specific phenotypic characteristics associated with commonly occurring mutations
Mutation screening revealed 31 different mutations in 68 patients and 12 non-pathogenic polymorphisms.
In this study, the MECP2 sequences in 121 unrelated Chinese patients with classical or atypical RTT were screened for deletions and mutations. In all, we identified 45 different MECP2 mutations in 102 of these RTT patients.
Mutations in MECP2 were found in about 55%
We identified mutations in the MECP2 gene and documented the clinical manifestations in 65 Rett syndrome patients to characterize the genotype-phenotype spectrum.
We searched for mutations by sequencing the MECP2 coding region in 45 sporadic cases (35 with classic RTT, eight with variant forms and two males) and in seven families with two or more affected females. Following our previous report of mutations in two families and eight sporadic cases, we here present 18 additional mutations.
The responsible gene, encoding methyl-CpG binding protein 2 (MeCP2), was recently discovered. Here we explore the spectrum of phenotypes resulting from MECP2 mutations. Both nonsense (R168X and R255X) and missense (R106W and R306C) mutations have been found, with multiple recurrences.
Mutations were identified in 44/55 (80%) unrelated classical sporadic and familial RTT patients, but only 1/5 (20%) sporadic cases with suggestive but non-diagnostic features of RTT
Collectively, we tested 228 unrelated female patients with a diagnosis of possible (209) or classic (19) RTT and found MECP2 mutations in 83 (40%) of 209 and 16 (84%) of 19 of the patients, respectively. Thirty-two different mutations were identified (8 missense, 9 nonsense, 1 splice site, and 14 frameshifts), of which 12 are novel and 9 recurrent in unrelated patients.
Mutations in MECP2 were identified from most of the patients with classical and variant RTT (25 of 27 cases)
In our series, 19 different de novo MECP2 mutations, eight of which were previously unreported, were found in 35 out of 50 Rett girls (70%)
Causative mutations in the MeCP2 gene were identified in 63% of patients, representing a total of 30 different mutations. Mutations were identified in 72% of patients with classical RTT and one third of atypical cases studied (8 of 25).
We have identified 15 different MECP2 mutations in 26 of 30 Danish RTT patients.

Answer: The neurodevelopmental disorder named Rett syndrome, originally termed as cerebroatrophic hyperammonemia. Although most exclusively affects females, has also been found in male patients.
Exact answer: Rett syndrome