Macrocephaly_Megalencephaly
Gene: ATP7A
Well established gene-disease association. Macrocephaly is a feature.
ATP7A-related copper transport disorders are classically separated in three pathologies according to their severity, all inherited in an X-linked recessive manner: Menkes disease (MD, OMIM #309400) which represent more than 90% of cases; occipital Horn Syndrome (OHS, OMIM #304150) and ATP7A-related distal motor neuropathy also named X-linked distal spinal muscular atrophy-3 (SMAX3, OMIM #300489). Although there is no clear cut correlation between Cu and ceruloplasmin levels in ATP7A related disorders, these three entities probably represent a continuum partly depending on residual functional ATP7A protein.
Menkes disease typically presents in infancy, and if untreated is fatal. Typical age at diagnosis is ~8 months.
Females are typically asymptomatic.
In Australia, the birth incidence of MD is reported to be much higher (1/40,000-100,000 cf 1 in 300,000 elsewhere), which may be due to a founder effect.
Non-genetic confirmatory testing: serum ceruloplasmin and copper, plasma catechols
Treatment: subcutaneous injections of copper histidine or copper chloride
ClinGen has assessed as moderate evidence for actionability.
Neonatal treatment with subcutaneous copper-histidine (initiated before 30 days of life) is recommended for asymptomatic males with a diagnosis of MD, but is not recommended for symptomatic boys or after 30 days of life. Treatment should be continued indefinitely. In an open-label clinical trial, 12 patients with MD treated with copper-histidine within 22 days of life had 92% survival after a mean follow-up of 4.6 years compared to 13% in a historical control group of 15 patients treated after a late diagnosis (mean age at diagnosis: 163 ± 113 days, range: 42 to 390). Two of the 12 patients with earlier treatment had normal neurological development. A second open-label trial of 35 presymptomatic patients receiving copper-histidine at less than a month of age reported significant improvement of four major neurodevelopmental (gross motor, fine motor/adaptive, personal/social, and language) domains and a non-significant lower mortality (28.5% vs 50%) at age of 3 years (or age of death) compared to 22 patients treated later and after onset of symptoms.Created: 23 Sep 2022, 2:52 a.m. | Last Modified: 23 Sep 2022, 2:52 a.m.
Panel Version: 0.119
Mode of inheritance
X-LINKED: hemizygous mutation in males, biallelic mutations in females
Phenotypes
Menkes disease MIM#309400
Gene: atp7a has been classified as Green List (High Evidence).
Phenotypes for gene: ATP7A were changed from to Menkes disease MIM#309400
Mode of inheritance for gene: ATP7A was changed from Unknown to X-LINKED: hemizygous mutation in males, biallelic mutations in females
Tag treatable tag was added to gene: ATP7A.
gene: ATP7A was added gene: ATP7A was added to Macrocephaly/Megalencephaly_VCGS. Sources: Expert Review Green,Victorian Clinical Genetics Services Mode of inheritance for gene: ATP7A was set to Unknown